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




Can we say "Could" is used for Future possibility ?

Hello nsnaveensorout,

Yes, that's one use of 'could'. It can describe present or future possibility, as the first two examples on the page show:

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

They could come by car. (= Maybe they will come by car.) - future possibility

They could be at home. (= Maybe they are at home.) - present possibility



The LearnEnglish Team

Sir sometimes I see you said 'you could use', what is the difference between you can use and you could use?

You can use 'but' to join these as one sentence.
You could use 'but' to join these as one sentence

Hello Dwishiren,

When we make suggestions both are often possible and have verb similar meanings. We can use can with a general (this is possible) or specific meaning, while could tends to be specific to a situation (in this situation it is possible).



The LearnEnglish Team

Hi sir.I wondering what 'could' means in the following sentences?

Drive carefully or you could have an accident.
David is coming to visiting. He could stay with us.

Hi Crokong,

You have two different uses here.

In the first example, could expresses possibility and has a similar meaning to might: this is something that has a chance of happening.

In the second example the meaning is also about possibility but in the sense of making an offer or a proposal. Here, it has a similar meaning to able to: we are able to give him a place to stay.



The LearnEnglish Team

the sentence: If Jones was at work until six, he couldn't have done the murder. is right according the conditionals rules?

Hi mary_1565,

Yes, it's grammatically correct :)


The LearnEnglish Team

Hello The LearnEnglish Team,
I would appreciate it if could help me understand why "CAN" is used in these context below, i mean, what "CAN" means here e.g. possibility, permession....

We help you progress quickly because of the intensity of the training. You CAN expect to be taught in a safe invironment, with the minimum of risk.

Hello BobMux,

I'd say that is a general statement about what is possible.

All the best,


The LearnEnglish Team