The modal verbs are can, could, may, might, mustshall, should, will and would.

The modals are used to show that we believe something is certain, probable or possible:

Possibility:

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

They might come later. (= Perhaps/Maybe they will come later.)
They may come by car. (= Perhaps/Maybe they will come by car.)
If we don’t hurry we could be late. (= Perhaps/Maybe we will be late)

We use could have, might have and may have to show that something was possible now or at some time in the past:

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

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 the modal 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)

Impossibility:

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.

Probability:

We use the modal must to show we are sure something to be true and we have reasons for our belief:

It’s getting dark. It must be quite late.
You haven’t eaten all day. You must be hungry.

We use must have for the past:

They hadn’t eaten all day. They must have been hungry.
You look happy. You must have heard the good news.

We use the modal should to suggest that something is true or will be true in the future, and to show you have reasons for your suggestion:

Ask Miranda. She should know.
It's nearly six o'clock. They should arrive soon.

We use should have to talk about the past:

It's nearly eleven o'clock. They should have arrived by now.

Exercise

Comments

Hi sir,

In this sentence 'You could lose your way in the dark. ' , I can't get the aspect. Could you please explain the context . Because I can't understand the usage of could in the past possibility.

Thanks

Hi TJ,

It's important to remember that modal verbs have multiple uses. One use of 'could' is as the past form of 'can' to describe possibility. It's helpful to compare the two:

When it is foggy people can easily get lost on their way home.

I lived in Scotland as a child and it was often foggy, so people could easily get lost on their way home.

The first sentence describes something that is generally possible (getting lost) in certain situations (when it is foggy). The second sentence describes something that was generally possible (getting lost) in certain situations (when it was foggy).

 

Peter

The LearnEnglish Team

got it, clear. Thanks for the quick reply.

cheers

Hi
If I am sure that I did well in exams ,can I say :"I am sure I passed" ?
or something else

Hello Hamdy Ali,

Yes, that is right. Both 'I'm sure' and 'I'm confident' are common ways to experss this. Good work!

All the best,
Kirk
The LearnEnglish Team

If we don’t hurry we could be late. why we use be with could?
as per Learn English We use the modals could, might and may to show that something is possible in the future, but not certain

Hello Alaul Mechanical,

As the explanation says, 'we use the modals could, might and may to show that something is possible in the future, but not certain'.

If we don't hurry we could be late.

Here, it is not certain that we will be late but it is possible. You could replace 'could' here with 'might' or 'may'

If we don't hurry we might be late.

If we don't hurry we may be late.

 

If we use 'will' here then the meaning changes:

If we don't hurry we will be late.

Now the speaker is sure that they will not be on time if they do not hurry. There is no doubt or uncertainty; it is certain and not just possible.

 

Best wishes,

Peter

The LearnEnglish Team

sir please explain "must+be+ing" with some examples in the context.

Hello Ali Sahir,

I'm afraid we can't provide long explanations like this in the comments sections. 'Must' has many uses. If you have an example which you have found which you would like us to explain or comment on then please post that in a reply and we'll be happy to answer.

 

Best wishes,

Peter

The LearnEnglish Team

sir, we can write ' it may/might/could rain tomorrow.' but is it right to say ' it would rain tomorrow.' can we use 'would' for future possibility? please answer..

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