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'can' and 'could'

Level: beginner

Possibility and impossibility

We use could to show that something is possible, but not certain:

They could come by car. (= Maybe they will come by car.)
They could be at home. (= Maybe they are at home.)

We use can to make general statements about what is possible:

It can be very cold here in winter. (= It is sometimes very cold here in winter.)
You can easily get lost in this town. (= People often get lost in this town.)

We use can't or cannot to say that something is impossible:

That can't be true.
You cannot be serious.

Level: intermediate

We use could have to make guesses about the past:

It's ten o'clock. They could have arrived by now.
Where are they? They could have got lost.

We use could to make general statements about the past:

It could be very cold there in winter. (= It was sometimes very cold there in winter.)
You could easily get lost in that town. (= People often got lost in that town.)

We use can't have or couldn't have to say that a past event was impossible:

They know the way here. They can't have got lost!
If Jones was at work until six, he couldn't have done the murder.


Level: beginner

We use can and can't to talk about someone's skill or general abilities:

She can speak several languages.
He can swim like a fish.
They can't dance very well.

We use can and can't to talk about the ability to do something at a specific time in the present or future:

I can see you.
Help! I can't breathe.

We use could and couldn't to talk about the past:

She could speak several languages.
They couldn't dance very well.

Level: intermediate

We use could have to say that someone had the ability or opportunity to do something, but did not do it:

She could have learned Swahili, but she didn't want to.
I could have danced all night. [but I didn't]


Level: beginner

We use can to ask for permission to do something:

Can I ask a question, please?
Can we go home now?

could is more formal and polite than can:

Could I ask a question please?
Could we go home now?

We use can to give permission:

You can go home now.
You can borrow my pen if you like.

We use can to say that someone has permission to do something:

We can go out whenever we want.
Students can travel for free.

We use can't to refuse permission or say that someone does not have permission:

You can't go home yet.
Students can't travel for free.


We use could you … as a polite way of telling or asking someone to do something:

Could you take a message, please?
Could I have my bill, please?

can is less polite:

Can you take a message, please?


We use can I … to make offers:

Can I help you?
Can I do that for you?

We sometimes say I can ... or I could ... to make an offer:

I can do that for you if you like.
I could give you a lift to the station.


We use could to make suggestions:

We could meet at the weekend.
You could eat out tonight.

Questions and negatives

We make questions by putting the subject after can/could:

Can I ...?
Could I ...?
Can you ...?
Could you ...?


The negative form is can't in spoken English and cannot in written English.

We sometimes say cannot, but it is very emphatic.

The negative form of could is couldn't in spoken English and could not in written English.

can and could: possibility 1


can and could: possibility 2


can and could: other uses 1


can and could: other uses 2




Hi Peter,
Thank you so much for the Help.

Hi Team,
I'm really surprised to see this kind of an active helpful site :) Hats off to the Team behind this org.
And this is my doubt, what is the actual meaning of "One of a kind"?
Is it mean like there is nothing like this kind or these all are the same kind.
Could you please help me on this.
Thank you

Hi Sanover,
Thanks for your compliment - we appreciate it! If you enter 'one of a kind' into the 'Cambridge Dictionaries Online' box at the right-hand side of the page, you should see the answer to your question.
Best wishes,
The LearnEnglish Team

Hi Adam,
Yeah :) Thanks alot for your prompt reply.
Thank you.

Hi Sir,
Please clarify about the different between 'Why can we ...?' and 'Why we can...?'
Thank you.

Hi,'Why can we...?' is the normal word order for questions:'Why can we have a free day on Saturday, but not on Monday?'

'Why we can...?' does not seem a correct alternative to me.  It could appear in an indirect question such as 'Can you tell me why we can...?', but not by itself.

I hope that answers your question.

Best wishes,



The LearnEnglish Team

Hi Peter
Thanks for your explanation.  This is really clear to me now.
Best regards,

which one is correct?
we can celebrate our birthdays together?
we could celebrate our birthdays together?
please reply asap

and also, for eg if some-one suggests something to me. so should my reply be "yeah I can do that" OR "yeah I could do that"

Hello kamrina,

Both are possible.  'Can' makes it sound like the possibility is much more likely, so sounds a little more enthusiastic, whereas 'could' can sound slightly more hesitant.  However, these are very minor differences, and often the way that you say it (the pronunciation) is more important than the choice of 'can' or 'could'.

I hope that clarifies it for you.

Best wishes,



The LearnEnglish Team