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

Section: 

Comments

Good day !

what tense is `must have been´ ?

Hello mgfielrocha,

In 'must have been', 'have been' is a perfect infinitive, which in this case is used to speak about the past, but as far as I know there is no name for the tense in this form. This is because 'must' and most modals don't really have tenses -- we have to use other words to express the same idea in a different time. For example, to speak about past obligation, we have to use 'had to' instead of 'must'.

If you're interested in learning more about this, the Wikipedia English modal verbs page would be a good place to start.

All the best,
Kirk
The LearnEnglish Team

Hi sir, can we use 'could' to make a statement in the future? E.g; I could have been driving home before she arrives on Monday.

Hi judeee,

You can use 'could' with future reference, but not 'could have'.

 

 

Best wishes,

Peter

The LearnEnglish Team

Dear admin,
Is it grammatically correct to write " May your happiness will never last " ?

Hello duffyzee,

I'm afraid that sentence is not grammatically correct. The problem is that you can't use two modal verbs ('may' and 'will') together in this way. Perhaps you mean 'may your happiness never last'? Or 'may your happiness never end'?

All the best,
Kirk
The LearnEnglish Team

Hi Kirk
Is 'will' modal verb or auxiliary one? According your answer to last comment, be understood that maybe there is no difference between auxiliary and modal verb. I'm getting mixed up, distinguish the difference of the modal and auxiliary verb, please.

Hello Fatemeh Roostaei,

Auxiliary verbs are helper verbs which occur with a main verb in order to create tenses, moods, aspects and voices. 

A modal verb is one kind of auxiliary verb. There are other auxiliary verbs which are not modals, such as 'did', 'do' and 'have' in these examples:

Did he go there?

I don't care.

I've got ten pounds.

 

Best wishes,

Peter

The LearnEnglish Team

Dear the English learner team

Could you please explain what are the differences between these sentences.
and what are the role of the verbs (has to, might, if + will and either+have to) as I always make mistake when I use these verbs. Thank you

1. Ali has to wake up at 8:00 am tomorrow.

2. If Ali wakes up late tomorrow, he might miss the train.

3. if it rains on Friday, the party will be cancelled.

4. Either the party will be cancelled, or they have to move it indoors.

Hello Diya,

It would take quite a long time to answer all of your questions thoroughly! To start with, I'm going to suggest some pages that I think will help you. After you've read through them, if you'd like to ask us a specific question, please let us know.

First of all, you can learn about 'have to' on our Modals 1 page. Our Conditionals 1 and 2 pages explain sentences that begin with 'if'. Finally, for 'either ... or', I'd recommend the Cambridge Dictionary's page on this topic.

All the best,
Kirk
The LearnEnglish Team

Pages