Modals expressing supposition

There are 8 modals expressing supposition, proba­bility or possibility to various degrees: must, may, might, should, ought to, can, could, will.

6.15.2.1. Must

Must expresses certainty, assurance, almost a convic­tion, i.e. the highest degree of supposition. For example:

Where is he? — He must be in the library. (=1 am sure he is in the library.) You must feel tired after your long walk. You must be the new teacher. (=1 suppose you are.) The meal must be ready by now. (=1 am sure it is.)

To refer an action to the past must takes a perfect infinitive: / saw him a few years ago. He must have been forty. There's nobody here — they must have all gone home. They must have known about it.

The negative form of must as a modal of supposition is cannot/can't. He can't be in the library. You can't be the new teacher. You can't be hungry after dinner.

In the past cannot/can't or couldn't take a perfect infinitive: They can't have known about it. He couldn't have been in the library.

6.15.2.2. Ought to/should

Ought to and should can be often used in the same contexts as less strong forms of must expressing milder supposition. For example: He should/ought to be in the library now. (=He is probably in the library.) She has been studying very hard, so she should/ought to pass her examination.

In this meaning should and ought to are mainly used in the positive sentences to refer actions to the present or future.

6.15.2.3. May/might

Although might is historically the past form of may in Modern English both may and might generally function independently.

In the third person singular their forms are may and might. They never take an auxiliary to form questions and negations. The negative forms of may and might are may not/mayn 't and might not/mightn 't.

As compared with must, may and might express a less degree of supposition, possibility, and probability: He may/might come or he may not/might not. We will do whatever may/might be necessary. I may/might see you tonight; I don't know yet. He may/might be having lunch.

To refer an action to the past may and might take a perfect infinitive. For example: Why hasn't she come? — She may/might have stopped to talk to someone. She may/might have missed the train.

Although may and might are similar in meaning and in most cases interchangeable might sometimes suggests a smaller possibility than may: Compare: He might come, but it is very unlikely. That car nearly hit me; I might have been killed.

In the indirect speech might can also be used as the past form of may. I thought it might rain. (=1 thought, «It may rain».)

Might is often used as a synonym to should and ought to: You might at least say 'good-by' when you leave. You might have offered to carry her suitcase.

6.15.2.4. Can/could

Although etymologically could is the past form of can, in Modern English they are often used on their own.

In the third person singular their forms are can and could. They need not an auxiliary to form questions and negations. Their negative forms are cannot/can't and could not/couldn 't.

Can is used to show possibility. For example: / am sure they can find a solution. He is confident that the problem can be settled. This word can't be used in such a context. Can this be true? This can't be true.

Can is not usually used to express uncertainty. In­stead may/might and less commonly could are used: He may/might/could have lost the papers. The papers may/ might/could be lost. The car may/might/could have broken down.

Could expresses uncertainty, probability: What shall we do tonight? — We could go to the theatre. What will you do tomorrow? — We could have a party. When shall we meet? — We could meet on Sunday. I don't know how managed to do the work. I couldn 't do it.

Can is also possible in the above contexts but it is more certain than could. We can go to the theatre. We can have a party. We can meet on Sunday.

To refer an action to the past could takes a perfect infinitive: We could have gone to the theatre last night but we decided not to. We couldn't have chosen a worse day for the picnic — it rained nonstop.

Could can be used like may and might denoting uncertainty but it is less common: The line is engaged. He may/might/could be talking to someone. He may/might/ could be trying to phone me while I'm phoning him.

6.15.2.5. Will

Will may express various degrees of possibility: strong supposition, assurance and be equivalent to must and certainty being synonymous to can. For example: This will be the postman at the door now. Why are we overdrawn? — This will be the desk we bought, it's too

expensive. (=must) This car mil hold five people comfor­tably. (=can)

⇐ Предыдущая891011121314151617Следующая ⇒

Поделиться: