You are here

'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




Hello Oleg

Yes, that's correct -- good work!

All the best


The LearnEnglish Team

Hello Oleg

It sounds to me as if you're talking about a possibility that you're not certain of; in this kind of situation, 'can' is not correct -- I would suggest 'could' instead. 

All the best


The LearnEnglish Team

if she is single today, i could have married her.
Am i correct?
means - the ga
if this gal is unmarried , i can mry

Hello Ali. Chy

No, I'm afraid that's not correct. I'm not completely sure what you want to say, but 'If she is single, I could marry her' is grammatically correct and logical.

All the best


The LearnEnglish Team

What would be the correct way of asking a teacher to meet me the next day?

1. May I meet you tomorrow, please?

2. Could we meet tomorrow, please?

3. May we meet tomorrow, please?

Hello Sheena virmani

Those are all fine, but I would recommend 2 -- it's probably the most common way to phrase a request like this. Or if you want to be more formal, 1 is more appropriate.

All the best


The LearnEnglish Team

Could you please guys open the questions and answers for will and would topic . we're a group of students and we would like just to review them and won't ask any questions please.

Hello Hayder991
Thanks for your comment. We recently updated that page and must have inadvertently turned off the comments. I've just fixed this, so you and other people can now make comments on that page. Thanks for letting us know!
All the best
The LearnEnglish Team

Hello Hayder991
I'm sorry about that. If you want to ask any questions, please don't hesitate. The explanation on the new page is more complete. I'd also recommend the Talking about the future page ( Many of the forms on that page are not 'will', but often people study them at the some time.
Good luck to all of you on your exam!
All the best
The LearnEnglish Team

Sir, I want to ask what form of tense should we use in this sentence with could?
"He was Martyred in prostration because no one could 'Killed' him in battle"