Modal verbs

POSSIBILITY: CAN, COULD, MAY, MIGHT

1. You use can to say that something is possible.

In some cases this can cause difficulty.

2. You use could, might, may to indicate that you are not certain whether something is possible, but you think it is. There is no important difference in meaning between these modals, but may is slightly more formal.

He might come.

They may help us.

That could be no reason.

You can also use ‘might not’ or ‘may not’ in this way, but ‘could not’ normally refers to the ability in the past.

3. When there is a possibility that something happened in the past, but you are not certain if it actually happened, you use could, may, might and Perfect Infinitive.

It could have been tomato soup.

You can also use ‘might not’, ‘may not’, followed by Perfect Infinitive in this way. But you can’t use “couldn’t’ in this sense.

He might not have seen me.

Может быть, он меня не видел.

They may not have done it.

Возможно, они этого не сделали.

NOTE: you use couldn’t + Perfect Infinitive when you want to indicate that it is not possible that something happened.

He didn’t have a car, so he couldn’t have given you a lift.

У него не было машины, не может быть, чтобы он тебя подбросил.

4. If you ask a question, whether it’s possible that something happened in the past, you use ‘could + Perfect Infinitive’

Could she have forgotten about me?

Неужели она забыла обо мне?

5. ‘Be able to’, ‘not be able to’, ‘be unable to’ are sometimes used instead of ‘can’ and ‘cannot’, for example after another modal verb, or when you want to use a ‘to’- Infinitive, an – ing form or a past participle.

PROBABILITY/CERTAINTY: must, ought to, should, will

1. When you want to say that something is probably true or that it will probably happen, you use should or ought to.

We should arrive by dinner time.

Мы, вероятно, приедем к обеду.

She ought to know.

Она, вероятно, знает.

2. When you want to say that you think something is probably not true or that it will probably not happen, you use should not or ought not to.

3. When you want to say that you are fairly sure that something happened in the past, you use should or ought to, followed by Perfect Infinitive.

They ought to have arrived yesterday.

Они, должно быть, уже приехали вчера.

4. When you want to say that you don’t think something happened, you use should not or ought not to + Perfect Infinitive.

This ought not to have been a problem.

Это не должно было представлять никаких затруднений.

NOTE: should or ought to + Perfect Infinitive can also be used when we expected something to happen, but it didn’t happen. We do not normally use the negative forms with this meaning.

She ought to have been home by now.

Она должна была уже быть дома (но ее нет).

5. When you are fairly sure that something is certainly true, you use ‘must’.

You must be Silvia’s husband.

Вы, должно быть, муж Сильвии.

He must know something about it.

Он наверняка что-то об этом знает.

6. If you are fairly sure that something is not true or is not the case, you use cannot or can’t.

This can’t be the whole story.

Не может быть, чтобы это было все.

7. When you want to say that you are almost sure that something happened in the past, you use must + Perfect Infinitive.

This article must have been written by a woman.

Эта статья наверняка написана женщиной.

8. To say that you don’t think that something happened, you use can’t or couldn’t +Perfect Infinitive.

You can’t have forgotten me.

Не может быть, чтобы вы меня забыли.

9. You use will to say that something is certain to happen in the future.

They’ll manage.

Они справятся.

You use will not or won’t to say that something is certain not to happen.

You won’t get much sympathy from them.

Не жди от них сочувствия.

ABILITY- CAN, COULD, BE ABLE TO

• We use can to talk about ability in the present.

• We use could to talk about ability in the past.

• We use be able to to talk about ability in the present, future and past.

1. We use can to say that someone has the ability to do something. Here we speak mainly about physical or mental ability. In this meaning it can be used only with the Indefinite Infinitive.

You can read and write.

We use cannot or can’t to say that they do not have the ability to do something.

He cannot dance.

If we want to emphasize the difficulty or to suggest a great effort we use manage to or succeed in + ing

2. When we want to talk about someone’s ability in the past as a result of a skill they had or did not have we use could, could not or couldn’t.

He could run faster than anyone else.

A lot of them couldn’t write or read.

3. We also use be able to, not to be able to, be unable to to talk about someone’s ability to do something but can or could are more common.

They are not able to run very fast.

We use was able to or were able to to say that someone managed to do something in a particular situation in the past.

After treatment he was able to return to work.

We were able to find time to discuss it.

WARNING: we do not normally use could to say that someone managed to do something in a particular situation. However we can use could not or couldn’t to say that someone did not manage to do something in a particular situation.

We couldn’t stop laughing.

In most cases we can choose to use either can or be able to. However we sometimes have to use be able to.

We have to use be able to if we are using another modal, or if we want to use - ing form, past participle or to-infinitive.

Nobody else will be able to read it.

…the satisfaction of being able to do the job.

4. When we want to say that someone had the ability to do something in the past but didn’t do it we use could + Perfect Infinitive.

You could have given it to me.

You know, she could have done French.

We often use this form when we want to express disapproval about something that was not done. (Reproach)

You could have told me.

5. We also use can or could with verbs such as see, hear, smell to say that someone is or was aware of something through one of their senses.