Топик: Сравнительные степени прилагательных и наречий (Comparison) Модальные глаголы (Modal Verbs) Цепочки существительных (Атрибутивная, номинативная группа) (Chains of nouns)
Can, Could, Be able to
Can and could are modal auxiliary verbs. Be able to uses the verb "to be" as a main verb. It is not an auxiliary verb, but we look at it here for convenience.
Can
Can is an auxiliary verb, a modal auxiliary verb. We use "can" to:
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talk about possibility and ability
-
make requests
-
ask for or give permission
Structure of Can
subject + can + main verb
The main verb is always the bare infinitive (infinitive without "to").
|
subject |
auxiliary verb |
main verb | ||
| + | I |
can | play | tennis. |
| - | He |
cannot | play | tennis. |
|
can't | ||||
| ? |
Can | you | play | tennis? |
Notice that:
-
Can is invariable. There is only one form of can.
-
The main verb is always the bare infinitive.
Use of Can
can: Possibility and Ability
We use can to talk about what is possible, what we are able or free to do:
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She can drive a car.
-
John can speak Spanish.
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I cannot hear you. (I can't hear you.)
-
Can you hear me?
Normally, we use can for the present. But it is possible to use can when we make present decisions about future ability.
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Can you help me with my homework? (present)
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Sorry. I'm busy today. But I can help you tomorrow. (future)
can: Requests and Orders
We often use can in a question to ask somebody to do something. This is not a real question - we do not really want to know if the person is able to do something, we want them to do it! The use of can in this way is informal (mainly between friends and family):
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Can you make a cup of coffee, please.
-
Can you put the TV on.