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What If the Speed of Light and Sound Were Switched?

Video vocabulary

adjust

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US / əˈdʒʌst /

UK / əˈdʒʌst /

A2
  • verb
  • To change; to attain a desired state or function
  • To change so as to fit in with new conditions

bad

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US / bæd /

UK / bæd /

A1
  • adjecitve
  • Not good; wrong
  • Lacking in good morals; evil
  • No longer fresh; spoiled

able

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US / 'eɪbl /

UK / ˈebəl /

A2
  • adjecitve
  • Skilled; good at something
  • Having the ability to do something

message

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US / 'mesɪdʒ /

UK / ˈmɛsɪdʒ /

A2
  • noun
  • Main idea or theme in a story, book, or film
  • Piece of information that is told/given to someone
  • verb
  • To communicate using text

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

than

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US / ðən /

UK / ðən /

A1
  • conjunction
  • Used to compare two things that are not equal

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

turn

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US / tɜ:n /

UK / tɚn /

A1
  • noun
  • Place where changing of direction happens
  • Your time or chance to perform a duty
  • Your chance to play or do in say a game
  • Unexpected change, as in the weather
  • verb
  • To become (a particular age)
  • To become a different quality, color, etc.
  • To change the direction of something, e.g. a car
  • To move in an opposite direction or position
  • To shape metal with a spinning tool

chemical

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US / ˈkemɪkl /

UK / ˈkɛmɪkəl /

A2
  • adjecitve
  • Made of various elements
  • noun
  • Basic substance produced by mixing elements

essential

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US / ɪ'senʃl /

UK / ɪˈsɛnʃəl /

A2
  • adjecitve
  • Extremely or most important and necessary

neutron

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US / ˈnu:ˌtrɔn, ˈnju:- /

UK / ˈnuˌtrɑn, ˈnju- /

A1
  • noun
  • Charge and mass about equal to a proton; enters into the structure of the atomic nucleus

big

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US / bɪɡ /

UK / bɪɡ /

A1
  • adjecitve
  • Popular
  • Serious
  • Large

little

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US / 'lɪtl /

UK / ˈlɪtl /

A1
  • adjecitve
  • Being short in length of time
  • Not great in size, amount, or degree; small
  • Being very young or younger than others
  • adverb
  • By an amount or degree that is not very much
  • Not often; rarely
  • noun
  • A person's name

let

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US / let /

UK / lɛt /

A1
  • verb
  • To allow someone to do something
  • Introducing a suggestion to do something together
  • To rent a house, etc. to others

mention

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US / 'menʃn /

UK / ˈmɛnʃən /

A2
  • noun
  • Act of referring to or talking about something
  • verb
  • To refer to or talk or write about something

person

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US / 'pɜ:sn /

UK / 'pɜ:rsn /

A1
  • noun
  • Man, woman or child

rocket

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US / 'rɒkɪt /

UK / ˈrɑkɪt /

B1
  • noun
  • Powerful engine that releases hot gases
  • Dark green, hot-tasting salad leaf
  • Weapon shaped like a long tube carrying bombs
  • Vehicle transporting people or things into space
  • verb
  • To travel, increase, or rise very quickly

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

body

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US / ˈbɒd.i /

UK / ˈbɑdi /

A1
  • noun
  • An object distinct from other objects
  • A group of people involved in an activity together
  • Main part of something
  • A person's physical self

make

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US / meɪk /

UK / mek /

A1
  • noun
  • Product made by a particular company; brand
  • verb
  • To arrange or prepare something e.g. dinner
  • To get to (a place) on time
  • To gain the status of (teacher, lawyer, etc.)
  • To create something by putting things together
  • To earn a certain amount of money at a job
  • To cause or force a person to do something
  • To cause something to happen or be formed

order

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US / 'ɔ:də(r) /

UK / ˈɔrdɚ /

A1
  • noun
  • Religious or social group, as of nuns
  • Instructions to others to do what you want
  • State in which things are neat and organized
  • What you ask to buy, e.g. food in restaurant
  • Social or political control of an area
  • verb
  • To put things in a sequence, e.g. a, b, c
  • To give instructions to others to do what you want
  • To ask for something you want to buy, e.g. a meal

universe

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US / ˈju:nɪvɜ:s /

UK / ˈjunəˌvɚs /

B2
  • noun
  • All of space that contains planets and stars
  • Things surrounding a person, affecting their life

how

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US / haʊ /

UK / haʊ /

A1
  • adjecitve
  • To what degree? in what amount?
  • adverb
  • (Used to explain the way to do something)
  • exclamation
  • For what purpose or reason?
  • (Used to ask someone or something's condition)

kind

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US / kaɪnd /

UK / kaɪnd /

A1
  • adjecitve
  • In a caring and helpful manner
  • friendly and considerate
  • noun
  • One type of thing

live

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US / lɪv /

UK / liv /

A1
  • adjecitve
  • Being broadcast as events happen, not recorded
  • Carrying electric current; able to give a shock
  • Glowing because burning; hot
  • Not yet killed (for food)
  • adverb
  • (Music, drama) as it is performed
  • verb
  • To be alive
  • To experience a particular type of life
  • To make your home in a house or town

you

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US / jʊ /

UK / ju /

A1
  • pronoun
  • Person someone is speaking or writing to
  • Person or people in general

sake

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US / seɪk /

UK / sek /

A2
  • noun
  • Japanese rice wine
  • Interest or benefit of someone or something

delay

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US / dɪˈleɪ /

UK / dɪˈle /

A2
  • noun
  • Action of being late or happening later
  • verb
  • To wait some amount of time before doing something
  • To do something later than is planned or expected
  • To stop something from happening for a time

gravitational

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US / ˌgrævɪˈteɪʃənl /

UK / ˌɡrævɪˈteɪʃənl /

C1
  • adjecitve
  • Concerning the force of gravity

next

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US / nekst /

UK / nɛkst /

A1
  • adverb
  • The one that follows another in time or order
  • At a time or place directly after the present one
  • noun
  • The one that follows after
  • adjecitve
  • Immediately after the previous one
  • First occurrence after the present one

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

call

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US / kɔ:l /

UK / kɔl /

A1
  • noun
  • A order or request for action
  • The sound an animal makes, often when in danger
  • A correct prediction, e.g. a decision in a game
  • A short visit to a place or person
  • A decision by a referee or umpire in a game
  • verb
  • To make a request or order for action
  • (Animal) to make sounds to warn of danger
  • To announce the date of an election
  • To make a judgment about something
  • To give someone or something a name
  • To guess in advance the result or outcome
  • To visit a place or person for a short time
  • To phone someone
  • To speak, announce or shout in a loud voice

equator

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US / ɪ'kweɪtə(r) /

UK / ɪˈkwetɚ /

B1
  • noun
  • Geographical line at zero degrees latitude

far

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US / fɑ:(r) /

UK / fɑr /

A1
  • adjecitve
  • A long way away
  • Being a long way away
  • adverb
  • To a large degree or extent

where

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US / hwɛə /

UK / hwɛr, wɛr /

A1
  • conjunction
  • At or in the place which
  • In whatever place
  • pronoun
  • Word you use to ask the location of something

distance

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US / 'dɪstəns /

UK / ˈdɪstəns /

A2
  • noun
  • Lack of friendliness toward another person
  • Amount of space between two places or things
  • verb
  • To make it clear that you are not involved

game

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US / ɡeɪm /

UK / ɡem /

A1
  • noun
  • Activity with rules that people play to have fun
  • Birds and animals people hunt to kill and eat
  • Match between two teams

wave

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US / weɪv /

UK / wev /

A2
  • noun
  • Movement of sound, air or energy
  • Deep and strong emotion that is suddenly felt
  • Slightly curved shape in hair
  • Frequency of movement of objects together
  • Up and down movement of water in a lake or sea
  • Signal with your hand to say hello or goodbye
  • verb
  • To cause to move side to side or back and forth
  • To swing back and forth as a result of the wind
  • To move your hand or arm to say hello or goodbye

another

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US / əˈnʌðə(r) /

UK / əˈnʌðɚ /

A1
  • adjecitve
  • One more, but not this
  • determiner
  • One more added
  • pronoun
  • One more (thing)

environment

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US / ɪn'vaɪrənmənt /

UK / ɛnˈvaɪrənmənt, -ˈvaɪən- /

A1
  • noun
  • Natural world in which plants and animals live
  • The entire surrounding conditions of something

visual

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US / 'vɪʒʊəl /

UK / ˈvɪʒuəl /

A2
  • adjecitve
  • Of or relating to vision
  • noun
  • Pictures/images used to help audience understand

completely

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US / kəmˈpli:tli /

UK / kəmˈpliːtli /

A1
  • adverb
  • In every way or as much as possible

front

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US / frʌnt /

UK / frʌnt /

A1
  • adjecitve
  • Opposite of back; the forward part of an object
  • noun
  • Behavior not showing a person's true feelings
  • Area where fighting in a war is happening
  • Place where air of different temperatures meets
  • verb
  • To have the forward part facing something
  • To lead a group of people, usually a band

only

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US / ˈəunli /

UK / ˈonli /

A1
  • adverb
  • Just one; just that amount or thing; not more than
  • Not very important or serious
  • Just that type of thing, person
  • Short time ago; not before a certain time
  • conjunction
  • Except; but

and

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US / ənd /

UK / ənd, ən,ænd /

A1
  • conjunction
  • Used to refer to two or more things
  • Plus; in addition; on top of that
  • Used to introduce an action that follows another

until

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US / ənˈtɪl /

UK / ʌnˈtɪl /

A1
  • conjunction
  • Up to; to a time when something happens
  • preposition
  • Before (a specific time)

from

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US / frəm /

UK / frʌm, frɑm,frəm /

A1
  • preposition
  • Starting at a particular place, time or level

escape

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US / ɪ'skeɪp /

UK / ɪˈskep /

A2
  • noun
  • Act to briefly ignoring boring or bad things
  • The 'esc key' on a keyboard
  • Act of getting away from where you are being kept
  • verb
  • To avoid something undesirable, dangerous or bad
  • To get away from a place where you are being kept
  • (Gas, water) to come out from a pipe, container
  • To not to be noticed or remembered by someone

out

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US / aʊt /

UK / aʊt /

A1
  • adverb
  • No longer stylish (e.g. fashion)
  • Away from home, business, or the usual place
  • In a direction/movement away from inside or center
  • noun
  • Act when a batter cannot continue playing
  • verb
  • To tell people a secret

survival

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US / səˈvaɪvl /

UK / sɚˈvaɪvəl /

A2
  • noun
  • Act of continuing to exist when facing difficulty

someone

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US / ˈsʌmwʌn /

UK / ˈsʌmˌwʌn, -wən /

A1
  • pronoun
  • Person who is not known or named

story

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US / 'stɔ:rɪ /

UK / ˈstɔri, ˈstori /

A1
  • noun
  • One of many floors or levels in a building
  • Account or description of how something happened

always

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US / 'ɔ:lweɪz /

UK / ˈɔlwez,-wɪz,-wiz /

A1
  • adverb
  • For a very long time
  • At all times; in every situation
  • For ever

itself

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US / ɪtˈself /

UK / ɪtˈsɛlf /

A1
  • pronoun
  • Referring to it

will

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US / wɪl /

UK / wɪl /

A1
  • noun
  • Desire or choice of someone
  • Document saying who gets your money when you die
  • Strong desire to do something; determination
  • Desire to do something; strong wish to do
  • other
  • Used with verbs to express the future
  • verb
  • To leave property to someone after your death
  • To use mental effort to make something happen
  • Am (is, are) likely to do
  • To influence someone to do something
  • To make something happen by strongly wanting it

doppler

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US / ˈdɒplə /

UK / ˈdɑːplər /

A1

side

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US / saɪd /

UK / saɪd /

A1
  • adjecitve
  • In addition to the central or most important thing
  • Next to, or very close to, the right or left of
  • noun
  • Position or opinion that is opposite to another
  • Right or left part of a person's body
  • Feature of someone's personality
  • Straight edge of an object
  • One of two or more groups fighting each other
  • verb
  • To decide to agree with one point, not the other

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

new

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US / nju: /

UK / nu, nju /

A1
  • adjecitve
  • Not old, recently born, built or made
  • Being or doing something for the first time
  • Not felt, seen or known previously
  • Having been recently bought or obtained

try

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US / traɪ /

UK / traɪ /

A1
  • noun
  • Act of putting the ball over the rugby goal line
  • verb
  • To make an effort, to attempt to do something
  • To examine someone or something in a court of law
  • To test to see if it is good or you like it
  • To make a person go through hardship; test
  • To examine something to see if it works

imagine

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US / ɪ'mædʒɪn /

UK / ɪˈmædʒɪn /

A1
  • verb
  • To think creatively about; form mental picture of

inside

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US / ˌɪn'saɪd /

UK / ɪnˈsaɪd, ˈɪnˌsaɪd /

A2
  • adjecitve
  • Being in something
  • Being in a building
  • adverb
  • Into a house; indoors
  • noun
  • Inner part or surface of something

million

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US / ˈmɪljən /

UK / ˈmɪljən /

A1
  • number
  • 1,000,000

explain

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US / ɪk'spleɪn /

UK / ɪkˈsplen /

A1
  • verb
  • To make clear or easy to understand by describing

sure

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US / ʃʊə(r) /

UK / ʃʊr /

A1
  • adjecitve
  • Having no doubts about something
  • Have confidence in your own words or actions
  • Firmly established or held; being firm or stable
  • Being correct or true
  • adverb
  • What you say to agree willingly

switch

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US / swɪtʃ /

UK / swɪtʃ /

A2
  • noun
  • A change or shift from one method to another
  • Thing you move to turn electrical items on or off
  • Thin flexible piece of wood or stick
  • verb
  • To exchange or replace something for another thing

exactly

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US / ɪgˈzæktli /

UK / ɪɡˈzæktli /

A1
  • adverb
  • No more and no less than; precisely

difference

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US / 'dɪfrəns /

UK / ˈdɪfərəns, ˈdɪfrəns /

A1
  • noun
  • A thing or issue that people do not agree about
  • Not of the same kind; unlike other things

never

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US / 'nevə(r) /

UK / ˈnɛvɚ /

A1
  • adverb
  • Not ever; not at any time

send

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US / send /

UK / sɛnd /

A1
  • verb
  • To cause to behave or respond in a particular way
  • To cause mail or packages to go to another place
  • To move something quickly in a particular way
  • To give information or greetings to someone

just

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US / dʒʌst /

UK / dʒʌst /

A1
  • adjecitve
  • Proper or appropriate; as is deserved
  • Doing or being what is right or fair
  • Legally correct; having enough evidence
  • adverb
  • Almost; nearly
  • Exactly at the time of
  • Exactly (the same as, like)

talk

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US / tɔ:k /

UK / tɔk /

A1
  • noun
  • Style of speaking
  • Discussion between two countries
  • Giving information in front of people; lecture
  • Saying things or ideas to someone with words
  • verb
  • To make a formal speech about something
  • To say things or ideas to someone with words

depend

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US / dɪˈpend /

UK / dɪˈpend /

B1
  • verb
  • Be controlled or determined by (someone/something)

news

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US / nju:z /

UK / nu:z /

A1
  • noun
  • Broadcast on radio or TV about recent events
  • Information about recent events

cool

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US / ku:l /

UK / kul /

A1
  • adjecitve
  • Steady and calm when facing difficulties
  • Almost cold; not warm or hot
  • Smart or stylish in a way (young) people admire
  • Unfriendly in an indirect way; distant
  • verb
  • To make something decrease in temperature
  • (Of an emotion, etc.) to become less strongly felt

begin

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US / bɪ'ɡɪn /

UK / ˈbeɡɪn /

A1
  • verb
  • To do the first part of an action; to start

per

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US / pə(r) /

UK / pɚ /

A2
  • preposition
  • In the manner directed or suggested
  • For each; during each

sound

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US / saʊnd /

UK / saʊnd /

A1
  • adjecitve
  • Sensible, dependable and reliable
  • Unbroken or undisturbed, as of sleep
  • Firm or solid in structure
  • Sane; not mentally ill
  • Clearly reasoned; involving sense, good judgment
  • noun
  • Unique quality that characterizes a style of music
  • Waves traveling in air or water that can be heard
  • verb
  • To seem or appear to be, from what was said
  • To say in a clear deliberate manner
  • To make a noise, e.g. to ring a bell

such

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US / sʌtʃ /

UK / sʌtʃ /

A1
  • determiner
  • Being similar to
  • (Thing) as previously stated or referred to
  • adverb
  • (Used to emphasize the quality of an adjective)

disturb

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US / dɪˈstɜ:b /

UK / dɪˈstɜ:rb /

A2
  • other
  • To cause someone anxiety or fear
  • verb
  • To cause someone anxiety or fear
  • To stop someone from working or sleeping

limit

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US / 'lɪmɪt /

UK / ˈlɪmɪt /

A2
  • noun
  • Point beyond which it is not possible to go
  • verb
  • To stop or prevent an increase past a point

land

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US / lænd /

UK / lænd /

A1
  • noun
  • Region or country
  • Earth; the ground
  • verb
  • To arrive or cause a boat to arrive at the shore
  • To obtain or get something that you wanted
  • To (cause to) come down to the ground safely
  • To cause to arrive in a specific place or state

since

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US / sɪns /

UK / sɪns /

A1
  • adverb
  • At a point before the present time
  • conjunction
  • For this reason; because
  • preposition
  • From the time in the past that

well

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US / wel /

UK / wɛl /

A1
  • adjecitve
  • Being in a fortunate, good condition or state
  • Healthy and in good condition
  • adverb
  • In an acceptable, proper, or successful manner
  • In a complete, total, or full manner
  • A great and considerable degree
  • In a successful way, in a good or satisfactory way
  • exclamation
  • Used to begin or continue a particular statement
  • Used to show you want to start saying something
  • Used to express that you are waiting for a reply
  • You say this to change the topic of a conversation
  • Used to indicate you are making a final remark
  • noun
  • Long deep hole in the ground to get water
  • verb
  • To cause your eyes to fill with tears

hour

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US / 'aʊə(r) /

UK / aʊr /

A1
  • noun
  • 60 minutes
  • Particular time of the day
  • Fixed, regularly occurring time

light

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US / laɪt /

UK / laɪt /

A1
  • adjecitve
  • Being bright making it easy to see; not dark
  • Being pale and lacking darkness of color
  • Not heavy; weighing only a little
  • adverb
  • Carrying few bags when traveling
  • noun
  • A source of energy that makes a room or area bright
  • Way in which something or someone is understood
  • verb
  • To cause something to burn; put a burning match to
  • To provide a way to see ahead

observer

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US / əbˈzɜ:və(r) /

UK / əbˈzɜ:rvə(r) /

B1
  • noun
  • Someone whose job it is to watch or notice things

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

constant

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US / 'kɒnstənt /

UK / ˈkɑnstənt /

A2
  • adjecitve
  • Happening frequently or without pause
  • noun
  • Thing that happens always or at a regular rate

earth

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US / ɜ:θ /

UK / ɚθ /

A1
  • noun
  • Wire connecting an electrical device to the ground
  • The planet we live on
  • Soil in which we grow plants

strong

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US / strɒŋ /

UK / strɔŋ /

A1
  • adjecitve
  • (Of tea or beer) dark or thick
  • Having big muscles; physically powerful

under

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US / ˈʌndə(r) /

UK / ˈʌndɚ /

A1
  • adjecitve
  • In the same place as another thing, but lower
  • adverb
  • In a lower quantity or price than expected
  • preposition
  • According to the terms of an agreement or law
  • Managed or controlled by the authority of
  • Being of a lesser quality or amount than expected
  • Influenced or affected by something or someone
  • Less or lower in age, amount, size or number

system

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US / 'sɪstəm /

UK / ˈsɪstəm /

A1
  • adjecitve
  • Working in an organized, logical way
  • noun
  • Set of organized, planned ideas that work together

for

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US / fə(r) /

UK / fɔr,fə /

A1
  • preposition
  • Used to show the purpose, or need of something

time

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US / taɪm /

UK / taɪm /

A1
  • noun
  • Speed at which music is played; tempo
  • Point as shown on a clock, e.g. 3 p.m
  • Number of hours, minutes needed to do something
  • Occasion when something happens
  • Period or occasion that something occurred
  • Period in history or the past
  • Something measured in minutes, hours, days, etc.
  • How long an event takes; duration
  • verb
  • To check speed at which music is performed
  • To choose a specific moment to do something
  • To measure how long an event takes, e.g. a race
  • To schedule something to occur at a specific moment

through

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US / θru: /

UK / θru /

A2
  • adjecitve
  • having finished using or doing something
  • adverb
  • From the beginning of something until the end
  • preposition
  • Over, in, across an entire thing or place
  • Allowing you to pass between, or to
  • By a particular way or process; by the use of

why

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US / waɪ /

UK / hwaɪ, waɪ /

A1
  • adverb
  • Question word to ask for a reason
  • exclamation
  • (Used to express surprise or approval)

blue

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US / blu: /

UK / blu /

A1
  • adjecitve
  • Color of the clear sky
  • Feeling sad or down

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

enter

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US / 'entə(r) /

UK / ˈɛntɚ /

A1
  • verb
  • To start a career or an education
  • To become a competitor in a contest
  • To add or type information in a computer
  • To go into a room, building etc.

zip

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US / zɪp /

UK / zɪp /

B1
  • noun
  • Energy; vigor; determination
  • Way to say 'nothing' or 'zero'
  • Device with interlocking teeth to close pants, etc.
  • verb
  • To compress digital documents into one file
  • To move very quickly in a certain direction
  • To close using a zipper

usually

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US / ˈju:ʒuəli /

UK / ˈjuːʒuəli /

A1
  • adverb
  • Normally; regularly

video

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US / 'vɪdɪəʊ /

UK / ˈvɪdiˌo /

A2
  • adjecitve
  • Of a moving film, with sound
  • noun
  • Recording capturing action with sound
  • verb
  • To make a moving film of, with sound

yet

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US / jet /

UK / jɛt /

A1
  • adverb
  • At a later time (used after ‘not’)
  • (Used to emphasize that thing is, will be greater)
  • Eventually; at a future time
  • Until now; up to the present
  • conjunction
  • Adding to what has been said, often as a contrast

effect

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US / ɪ'fekt /

UK / ɪˈfɛkt /

A1
  • noun
  • An advantage, benefit
  • Change brought about by a cause; result

incredibly

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US / ɪnˈkredəbli /

UK / ɪnˈkrɛdəblɪ /

A2
  • adverb
  • To a great degree; very; amazingly

our

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US / 'aʊə(r) /

UK / aʊr /

A1
  • determiner
  • Belonging to us

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

survive

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US / sə'vaɪv /

UK / sɚˈvaɪv /

A2
  • verb
  • To continue to live despite illness or trouble

but

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US / bət /

UK / bʌt,bət /

A1
  • conjunction
  • Used before you say something different, opposite

good

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US / ɡʊd /

UK / ɡʊd /

A1
  • adjecitve
  • Proper, appropriate or right
  • (Of an amount) enough; plenty
  • Excellent; high quality
  • Acting well or properly; of moral character
  • In a positive or happy emotional state
  • noun
  • Advantage or benefit

signal

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US / 'sɪɡnəl /

UK / ˈsɪɡnəl /

A2
  • adjecitve
  • Most important or most noticeable
  • noun
  • Movement of a hand or other means to send messages
  • Act/sound that tells people to do/start something
  • Road-side lights that direct traffic to go or stop
  • Sound and light waves carrying TV and radio data
  • verb
  • To be evidence/an indication something will happen
  • To make a noise or motion to tell someone to start

single

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US / 'sɪŋɡl /

UK / ˈsɪŋɡəl /

A1
  • adjecitve
  • Being one only, without others
  • Only; merely
  • Not married or in a relationship
  • noun
  • One run in cricket or a hit baseball
  • An individual song from a CD or album
  • Person who is not married or in a relationship

star

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US / stɑ:(r) /

UK / stɑr /

A1
  • noun
  • Very famous person, usually an entertainer
  • Someone who does something very well
  • Your horoscope
  • A bright planet of hot gas in the night sky
  • A 5-6 sided asterisk-shape
  • verb
  • To perform or play a main role in a movie, play
  • To do something very well
  • To mark with a 5-6 sided asterisk-shape

experience

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US / ɪk'spɪərɪəns /

UK / ɪkˈspɪriəns /

A1
  • noun
  • Thing a person has done or that happened to them
  • An event at which you learned something
  • Knowledge gained by living life, doing new things
  • verb
  • To gain knowledge by doing things

planet

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US / 'plænɪt /

UK / ˈplænɪt /

A2
  • noun
  • One of the bodies that orbit the sun

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

physics

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US / ˈfɪzɪks /

UK / ˈfɪzɪks /

A1
  • other
  • The study of heat, light, and energy on objects

slow

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US / sləʊ /

UK / sloʊ /

A1
  • adjecitve
  • Lacking activity, busyness or excitement
  • (Clock) showing time earlier than the actual time
  • Having difficulty understanding simple things
  • Moving or happening without speed; not fast
  • verb
  • To move, with less speed than before
  • To move or go without much speed

anyone

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US / ˈeniwʌn /

UK / ˈɛniˌwʌn, -wən /

A1
  • pronoun
  • Any person

find

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US / faɪnd /

UK / faɪnd /

A1
  • noun
  • Object discovered by chance
  • Things that have been discovered from searching
  • verb
  • To become aware of something that is happening
  • To discover or meet by chance
  • To decide if someone is guilty of a crime, or not
  • To learn through study, research, or effort
  • To discover something by looking for it

exceed

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US / ɪk'si:d /

UK / ɪkˈsid /

B1
  • verb
  • To be greater in number, degree than something
  • To go above or beyond a limit or rule

great

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US / ɡreɪt /

UK / ɡret /

A1
  • adjecitve
  • Very large in size
  • Very important
  • Very good; fantastic; wonderful
  • adverb
  • Very good; better than before
  • noun
  • Successful and well-admired person

require

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US / rɪ'kwaɪə(r) /

UK / rɪˈkwaɪr /

A2
  • verb
  • To demand that someone does something
  • To need to do something, to make it necessary

least

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US / li:st /

UK / list /

A1
  • adverb
  • In the smallest or lowest way
  • noun
  • Something that is of the lowest or smallest degree

nothing

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US / 'nʌθɪŋ /

UK / ˈnʌθɪŋ /

A1
  • noun
  • Item of little or no value, importance, interest
  • Number or value of zero
  • pronoun
  • Not anything, not a single thing

tell

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US / tel /

UK / tɛl /

A1
  • verb
  • To (strongly) advise a person to do something
  • To be able to guess
  • To say or communicate information to someone
  • To inform, but without speaking; indicate
  • To have a negative effect on someone
  • To order someone to do something; command
  • To recognize something based on certain signs
  • To report something to an authority
  • To explain something or teach someone something

annoying

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US / əˈnɔɪɪŋ /

UK / əˈnɔɪɪŋ /

B1
  • adjecitve
  • A little angry; upset
  • verb
  • To make someone angry

first

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US / fɜ:st /

UK / fɚst /

A1
  • adjecitve
  • 1st; Coming before all others in time or place
  • noun
  • Something that has not happened before
  • Position of the winner of a competition

get

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US / ɡet /

UK / ɡɛt /

A1
  • verb
  • To become affected by illness or disease
  • To begin to feel or understand an emotion or idea
  • To send or bring someone or something home, etc.
  • To go somewhere to obtain something
  • To (cause to) do a particular thing
  • To obtain, receive or be given something
  • To currently have
  • To prepare for use
  • To understand something being said or read

medium

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US / 'mi:dɪəm /

UK / ˈmidiəm /

A2
  • noun
  • Method of expressing ideas or feelings
  • Something available in a middle size or condition
  • Person who claims to communicate with the dead

down

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US / daʊn /

UK / daʊn /

A1
  • adjecitve
  • Being sad, sick, or unhappy
  • Not operating, working, or functioning as expected
  • adverb
  • In a sitting or lying position
  • Towards or on the ground, floor, or bottom
  • Written or copied onto a piece of paper or book
  • noun
  • A period of play in American Football
  • The soft, smooth hairs that cover a bird's body
  • preposition
  • Along something's path, course, or direction
  • Going from a higher position to a lower position
  • verb
  • To eat or drink very quickly and without stopping

decrease

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US / dɪˈkri:s /

UK / dɪˈkris /

B1
  • noun
  • Amount by which something has been reduced
  • verb
  • To reduce the size, amount or number of something

happen

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US / 'hæpən /

UK / ˈhæpən /

A1
  • verb
  • To take place or occur

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

even

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US / 'i:vn /

UK / ˈivən /

A1
  • adjecitve
  • Being equal in influence, power, possibility etc.
  • Being divided equally or fairly
  • (Of teams/contest) with similar chances of success
  • Smooth, level, or regular
  • Can be divided by 2; ending in 2, 4, 6, 8, or 0
  • At a regular, equally steady manner
  • Remaining steady and unchanging
  • adverb
  • (When this is surprising) as well; too
  • (Used to compare two things/stress the difference)
  • verb
  • To make something level; to flatten
  • To make something equal

different

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US / ˈdɪfrənt /

UK / ˈdɪfrənt /

A1
  • adjecitve
  • Not of the same kind; unlike other things

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

second

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US / 'sekənd /

UK / ˈsɛkənd /

A1
  • adjecitve
  • 2nd; the one following first
  • noun
  • Unit of time; one sixtieth of a minute
  • Short period of time that you wait for someone
  • (Do) soon

reaction

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US / rɪ'ækʃn /

UK / riˈækʃən /

A2
  • noun
  • Bodily response to a drug or something eaten
  • Feeling or action in response to something

that

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US / ðæt /

UK / ðæt, ðət /

A1
  • adjecitve
  • The person or thing being talked about
  • Used to identify something both the speakers know
  • adverb
  • Used to reinforce adjectives and adverbs
  • To such a degree
  • conjunction
  • Used to connect a noun clause
  • Used to introduce an adverbial clause
  • Used to introduce a noun clause
  • determiner
  • Used as a noun to refer to something
  • pronoun
  • Referring an object far away
  • Used to refer to the relative pronoun ‘which’

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

doom

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US / du:m /

UK / dum /

B2
  • noun
  • Certain of the failure or destruction of
  • Very bad, unhappy future event or situation
  • verb
  • To make failure, defeat or death certain for

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

moon

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US / mu:n /

UK / mun /

A2
  • noun
  • Round object circling the Earth at night
  • verb
  • To expose your buttocks as a joke

red

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US / red /

UK / rɛd /

A1
  • adjecitve
  • Being the color of blood

change

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US / tʃeɪndʒ /

UK / tʃendʒ /

A1
  • noun
  • Exchange of one set of clothes for another
  • Money in the form of coins instead of paper
  • Money returned after giving too much
  • Act of making or becoming something else
  • verb
  • To exchange one set of clothes for another
  • To exchange one kind of money for another
  • To replace something with another thing
  • To make or become something else
  • To go from one train, bus, etc. and go to another

pressure

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US / 'preʃə(r) /

UK / ˈprɛʃɚ /

A2
  • noun
  • Anxiety caused by difficult problems
  • Force, weight when pressing against a thing
  • Strong persuasion to do something
  • verb
  • To apply force to something
  • To persuade or force someone to do something

personally

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US / ˈpɜ:sənəli /

UK / ˈpəsənəli /

A2
  • adverb
  • By a specific person, and not by anyone else
  • Knowing someone as a friend, or closely

space

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US / speɪs /

UK / spes /

A1
  • noun
  • Empty area kept for a specific reason, like a car
  • Empty area with nothing in it
  • Area in the sky where the stars are
  • Area between written words on a page
  • verb
  • To make a certain distance or time between

travel

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US / ˈtrævl /

UK / ˈtrævəl /

A1
  • noun
  • Going to other places, esp. distant places
  • verb
  • To go to a place that is far away

dense

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US / dens /

UK / dɛns /

B1
  • adjecitve
  • Very thick and difficult to see, get through
  • Hard to understand
  • Uncomprehending; foolish; inconsiderate

dry

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US / draɪ /

UK / draɪ /

A1
  • adjecitve
  • (Of humor) clever, but not obvious; ironic
  • Without water; not wet
  • (Of wine, etc.) not sweet
  • Without butter or jam
  • verb
  • To remove liquid or water from something

possible

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US / ˈpɒsəbl /

UK / ˈpɑsəbəl /

A1
  • adjecitve
  • Being able or appropriate for a task or purpose
  • Having a chance of happening, or being true

speed

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US / spi:d /

UK / spid /

A2
  • noun
  • How fast or slow something is or is done
  • verb
  • To move quickly when completing an action
  • To drive a vehicle faster than laws allow

solar

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US / 'səʊlə(r) /

UK / ˈsolɚ /

B1
  • adjecitve
  • Concerning the sun, or its heat

all

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US / ɔ:l /

UK / ɔl /

A1
  • adverb
  • Completely; totally
  • determiner
  • Being every one of something
  • pronoun
  • 100% of something; the complete amount

metabolism

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US / məˈtæbəlɪzəm /

UK / mɪˈtæbəˌlɪzəm /

B2
  • noun
  • Chemical processes to convert food to energy

fast

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US / fɑ:st /

UK / fæst /

A1
  • adjecitve
  • In a way that is difficult to move or change
  • Moving or able to move quickly
  • Showing time that is later than the actual time
  • adverb
  • With a great deal of speed
  • noun
  • Period of time when a person chooses not to eat
  • verb
  • To refuse food for a long time

who

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US / hu: /

UK / hu /

A1
  • pronoun
  • Which person
  • Used to introduce information about people

work

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US / wɜ:k /

UK / wɚk /

A1
  • adjecitve
  • Activity completed in order to make money
  • noun
  • The product of some artistic or literary endeavor
  • Everything created by an author, artist, musician
  • Activity you do in order to make money
  • Place of employment
  • Final product or result of a some labor or effort
  • verb
  • To bring into a specific state of success
  • To be functioning properly, e.g. a car
  • To do your job in your company or workplace
  • To make an effort to do something
  • To operate a machine or device

take

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US / teɪk /

UK / tek /

A1
  • noun
  • Filming of a single scene for TV or the movies
  • verb
  • To accept something that is offered
  • To use a method of traveling, e.g. a bus or train
  • To use a camera to make (a photo)
  • To pick up something and go away with it
  • To study a subject in school
  • To attempt to pass (an exam)
  • To require a certain amount of time, money, space

move

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US / mu:v /

UK / muv /

A1
  • noun
  • Act of moving a playing piece in chess, etc.
  • An action; doing something
  • Step taken to achieve a goal
  • verb
  • To cause someone to have certain emotions
  • To cause something to change to a different place
  • To change where people live or a business operates
  • To take action to do or achieve something

between

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US / bɪˈtwi:n /

UK / bɪˈtwin /

A1
  • preposition
  • From one person, thing, or place, to another
  • In the space that separates two objects
  • Among two or more people who share something

everything

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US / 'evrɪθɪŋ /

UK / ˈɛvriˌθɪŋ /

A1
  • pronoun
  • All of the things mentioned

away

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US / ə'weɪ /

UK / əˈwe /

A1
  • adjecitve
  • Not present
  • adverb
  • Disappear completely
  • Doing something with a lot of energy
  • Not here; far from here; in a different direction
  • To a different area, location

world

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US / wɜ:ld /

UK / wɜrld /

A1
  • noun
  • All the humans, events, activities on the earth
  • Political division due to some kind of similarity

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

know

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US / nəʊ /

UK / noʊ /

A1
  • verb
  • To be familiar with a person or place, thing
  • To feel sure or be convinced about something
  • To discover or be aware of something
  • To be able to distinguish
  • To have knowledge of things

moment

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US / 'məʊmənt /

UK / 'moʊmənt /

A1
  • noun
  • Very short or brief period of time
  • A particular period in time

station

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US / 'steɪʃn /

UK / ˈsteʃən /

A1
  • noun
  • Building, area, place used for a specific reason
  • A person's place in society
  • Place where you can catch a train or a bus
  • Company that broadcasts radio or TV programs
  • verb
  • (Army) to be posted to a place to perform duties
  • To put a person in a certain place or position

car

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US / kɑ:(r) /

UK / kɑr /

A1
  • noun
  • A vehicle with wheels and engine to carry people

see

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US / si: /

UK / si /

A1
  • verb
  • To go on a date with someone
  • To predict whether something is, or will be true
  • To understand what someone says
  • To use your eyes to look at something
  • To visit a place often for sightseeing or pleasure
  • To visit or meet with someone
  • To find out by waiting or looking
  • To watch (a game, movie or TV show)

rely

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US / rɪ'laɪ /

UK / rɪˈlaɪ /

B2
  • verb
  • Depend on with full trust or confidence

air

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US / eə(r) /

UK / er /

A1
  • noun
  • Mixture of gases around the earth that we breathe
  • A person's manner intended to impress others
  • verb
  • To expose to the outside, to dry or freshen
  • To broadcast a TV or radio show
  • To open a subject to discussion and debate

challenge

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US / 'tʃælɪndʒ /

UK / ˈtʃæləndʒ /

A2
  • noun
  • An activity you wish to try that may be hard to do
  • Act of formally inviting someone to compete
  • A question to determine correctness of something
  • verb
  • To formally invite someone to compete at something
  • To question the correctness of something

break

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US / breɪk /

UK / brek /

A1
  • noun
  • Time you stop an activity before continuing
  • End of a relationship
  • An escape from a place such as a jail
  • (Lucky) advantage or benefit from something
  • Find a solution or answer to a problem or crime
  • Change in the weather
  • verb
  • To create a new record e.g. running the 100m dash
  • To form a crack in something
  • To burst or become damaged
  • To end a relationship
  • To escape from a place such as a jail
  • To train a wild animal e.g. a horse
  • To separate into pieces by force, or by dropping
  • To act against a law, rule, or promise
  • To become known suddenly, as in the news
  • To not do what you promised e.g. not keep promises
  • To solve a crime, or answer a problem
  • To stop functioning properly
  • To suddenly start, open or commence
  • To change in pitch suddenly, as in a voice
  • To fall on the shore, as in waves
  • To begin or change suddenly; the dawn or weather
  • To defeat by causing the person to lose their will

increase

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US / ɪn'kri:s /

UK / ɪnˈkris /

A1
  • noun
  • Fact of increasing; amount something grows by
  • verb
  • To make or become larger in size or amount

hear

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US / hɪə(r) /

UK / hɪr /

A1
  • verb
  • To be aware of sound; to perceive with the ear
  • To be told or find out information or facts
  • To consider or listen to a court case

almost

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US / 'ɔ:lməʊst /

UK / ˈɔlˌmost, ɔlˈmost /

A1
  • adverb
  • Only a little less than, nearly, not quite

before

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US / bɪˈfɔ:(r) /

UK / bɪˈfɔr,-ˈfor /

A1
  • adverb
  • At a time earlier than the present; previously
  • conjunction
  • In advance of something happening
  • preposition
  • In front of someone or something

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

part

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US / pɑ:t /

UK / pɑ:rt /

A1
  • adjecitve
  • To some degree; half; not fully
  • noun
  • Division of a book
  • Ratio of something, e.g. 3 of gin, 1 of tonic
  • A line in a person's hair, made with a comb
  • Character an actor plays on stage, movie, or TV
  • Some, but not all of a specific thing
  • Role in causing something to happen
  • verb
  • To make a line in a person's hair, by using a comb
  • To move two things apart creating a space
  • To leave someone, or to break off a relationship

end

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US / end /

UK / ɛnd /

A1
  • noun
  • The point where a process or activity stops
  • A point that marks the limit of something; finish
  • Goal or desired result
  • The tip, edge or limit of something
  • verb
  • To be the last part of something

universal

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US / ˌju:nɪˈvɜ:sl /

UK / ˌjunəˈvɚsəl /

A2
  • adjecitve
  • Existing in all places at all times for all people
  • Done or experienced by everyone
  • noun
  • Things which apply equally to everyone

accelerate

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US / əkˈseləreɪt /

UK / ækˈsɛləˌret /

B1
  • verb
  • To cause to occur earlier than expected
  • To increase the speed or rate of something

collapse

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US / kə'læps /

UK / kəˈlæps /

B1
  • verb
  • To fold (e.g. a stroller) down to make it smaller
  • To suddenly fall down or break apart into pieces
  • To fall down suddenly due to being ill or tired

mirror

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US / 'mɪrə(r) /

UK / ˈmɪrɚ /

A2
  • noun
  • Thing with glass surface used to look at yourself
  • An accurate impression or picture of something
  • verb
  • To reflect (an image)
  • To have similar qualities to something else

upon

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US / əˈpɔn, əpən /

UK / əˈpɑn, əˈpɔn /

A1
  • preposition
  • More formal term for 'on'

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together
  • Subtitles section
  • Nothing can travel faster than light.
  • But what if we switched the rules a little?
  • Imagine a world where the speed of light was slower, about the speed that sound travels at.
  • In turn, the sound in that hypothetical world would be accelerated until it reached the speed of light.
  • How would the sound sound, and the light look?
  • And why would that universe be doomed?
  • This is WHAT IF, and here's what would happen if the speed of light and sound switched.
  • Light travels at a constant speed of 300,000 km per second.
  • If you, personally, were able to travel at that kind of speed, you could zip around the Earth's equator 7.5 times in just one second.
  • If sound could travel that fast, well, we'll get to that part in a moment.
  • First, let me explain something.
  • There's one big difference between the speed of light and the speed of sound.
  • Light speed is a universal constant.
  • It's always the same for every observer.
  • For sound, it's different.
  • The speed of sound depends on the density of the medium it travels through.
  • What we usually refer to as the speed of sound is the speed of sound waves passing through dry air at 20 °C. That speed is 343 m per second.
  • And that's almost a million times slower than the speed of light.
  • If light traveled that slow, how different would our Universe have turned out to be?
  • Since light speed is a universal speed limit, changing it would completely change how the Universe works.
  • With the new speed limit of 343 m per second, everything would be so slow.
  • You'd find that moving at 0.2 km per hour would only be possible with a rocket, or at least a nuclear-powered car.
  • Driving it would be a challenge, as you wouldn't be able to see far ahead.
  • But you would experience a cool Doppler effect around you.
  • Things in front of your car would seem blue.
  • In your rearview mirror, everything would look red.
  • In that world, it would take hours to send a message to someone on the other side of the planet.
  • You know what would be even more annoying?
  • Talking to someone who's further than a hand's distance away from you.
  • The delays in visuals would make it look as if you were video calling someone with a bad signal, only in person.
  • We would never be able to make it to space, because to do that, we'd need to escape from the gravitational influence of Earth.
  • That requires the speed greater than the speed of light in our hypothetical world.
  • We'd never reach it to begin with.
  • There would be no moon landing, no solar system exploration, not even the International Space Station.
  • On a more disturbing note, the chemical reactions in your body would slow down.
  • That can't be good.
  • Essential functions like your metabolism depend on those reactions.
  • I can't tell you exactly how this would end, but it sure wouldn't take long.
  • All that, and we haven't even got to the speed of sound yet.
  • For the sake of your survival, let's say that your body adjusted to the slow motion inside it.
  • Now, sound enters the game.
  • It's faster than light now, so you would hear everything before you got to see it.
  • Because sound relies on the environment, in order for this to happen, air would have to turn incredibly dense.
  • We're talking as dense as neutron stars.
  • Not a single living organism would survive under such strong pressure.
  • Not to mention that all this breaks the rules of physics.
  • Nothing can exceed the universal speed limit, and if sound did travel faster, that's not good news for anyone.
  • The universe would collapse upon itself long before we got to experience that cool Doppler effect.
  • Next time, try increasing the speed of light instead of decreasing it.
  • That's a story for another WHAT IF.