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

It can be very cold in winter. (= It is sometimes very cold in winter)
You can easily lose your way in the dark. (= People often lose their way in the dark)

We use could as the past tense of can:

It could be very cold in winter. (=Sometimes it was very cold in winter.)
You could lose your way in the dark. (=People often lost their way in the dark)

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

If we don’t hurry we could be late. (=Perhaps/Maybe we will be late)

We use could have to show that something is/was possible now or at some time in the past:

It’s ten o’clock. They could have arrived now.
They could have arrived hours ago.


We use the negative can’t or cannot to show that something is impossible:

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

We use couldn’t/could not to talk about the past:

We knew it could not be true.
He was obviously joking. He could not be serious.


We use can 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 to talk about the ability to do something at a given time in the present or future:

You can make a lot of money if you are lucky.
Help. I can’t breathe.
They can run but they can’t hide.

We use could to talk about past time:

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



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 if you like.
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 free.

Instructions and requests:

We use could you and 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?

Offers and invitations:

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 can give you a lift to the station.





Hello sir, could you please tell me how to use can/could for invitations (with example)
Thank you.

Hello mmoaazhameed,

When the explanation above says 'offers and invitations', 'invitation' means essentially the same thing as 'offer'. So, for example, you could say to a person who looks lost on the street: 'Can I help you?' or 'Could I help you?' – these are offers or invitations to help.

Our sister site LearnEnglish Teens has a video that explains this grammar as well as a few additional practice exercises if you'd like to work on this more.

All the best,
The LearnEnglish Team

i have an other question. are both formations correct?

"the best you could say" vs "the best you can say"?
( you could say to a person who looks lost on the street or you can say........?)

Hello mmoaazhameed,

I'm not clear on the context of the sentence. Is this part of a dialogue? Has the person on the street asked you something? Before we can answer we need to know the context, as this is crucial in determining whether 'can', 'could' or both are correct.


Best wishes,


The LearnEnglish Team

thank alot kirk! :)

I have a question about this sentence "what we would do if the world was different" could it be possible if i replace the modal "would" in the example sentence with "could". What we could do if the world was different? How the could sentence differs from the former? Im really confused with can and will although there are some particular use of these modals but sometimes they are used in a sentence in which they can mean the same. how will i know if im going to use can and will. thank you very much

Thanks for the reply. Im still a bit confusedwhat if I used would and could like this "If we dont hurry we could be late" and "if we hurry we would not be late". Is it also possible that I use would in your example "if we dont hurry we would be late"? Is this mean that if I use could this means it is proble there is chance wherein if I use would you are going to be late and sure about it? Thank you

Hello RTris,

'Could' in these examples describes possibility while 'would' describes a sure result, provided the condition is fulfilled. However, your examples are conditional forms and the forms in the second clause must agree with the verb form in the first clause:

If we dont hurry we could be late - this describes a possibility; it is possible that we will be late

"If we hurry we would not be late - this sentence is not consistent. You can say 'If we hurry we will not be late' (describing the result of a possible or likely condition) or you can change the first clause and say 'If we hurried we would not be late' (describing the result of a hypothetical or unlikely condition).


Best wishes,


The LearnEnglish Team

Hello RTris,

Both 'would' and 'could' are possible. If we use 'would' then we are talking about our choices or decisions in a particular situation (a different world). If we use 'could' then we are talking about what is possible in that situation.

You can think of it like this: what we could do is everything that is possible; what we would do is which of those possible things we choose. For example:

If it rained I could stay at home or go out. I like walking in the rain, so I think I would go out.


Best wishes,


The LearnEnglish Team

Hey :) 2 questions please
1-Is this grammatically correct? 2- is it better to use could or can ?

"That story is the one that keeps me going whenever I hit my point or think that I ( couldn't ) do it anymore."