1. I'm sorry I won't come.
Correct answer 1: be able to
2. How possibly imagine that?
Correct answer 2: can you
3. Once I've passed my test I'll drive a car.
Correct answer 3: be able to
Объяснение:
Modal verb 'can'
Can is an auxiliary verb, a modal auxiliary verb. We use can to:
- talk about possibility and ability
- make requests
- ask for or give permission
The main verb is always the bare infinitive (infinitive without "to").
subject
auxiliary verb
main verb
+
I
can
play
tennis.
-
He
cannot/can't
play
tennis.
?
Can
you
play
tennis?
Use of can
Possibility and Ability
We use can to talk about what is possible, what we are able or free to do:
Normally, we use can for the present. But it is possible to use can when we make present decisions about future ability.
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).
Permission
We sometimes use can to ask or give permission for something.
(Note that we also use could, may, might for permission. The use of can for permission is informal.)
Be Able To
Although we look at be able to here, it is not a modal verb. It is simply the verb be plus an adjective (able) followed by the infinitive. We look at be able to here because we sometimes use it instead of can and could.
We use be able to to talk about ability.
Structure of be able to: subject + be + able + infinitive
subject
main verb be
able adjective
infinitive
+
I
am
able
to drive.
-
She
is not/isn't
able
to drive
?
Are
you
able
to drive?
Use of be able to
Ability
We use be able to to express ability. "Able" is an adjective meaning: having the power, skill or means to do something. If we say "I am able to swim", it is like saying "I can swim". We sometimes use "be able to" instead of "can" or "could" for ability. "Be able to" is possible in all tenses - but "can" is possible only in the present and "could" is possible only in the past for ability. In addition, "can" and "could" have no infinitive form. So we use "be able to" when we want to use other tenses or the infinitive.
Correct answer 1: must
Correct answer 2: can't
Correct answer 3: must
Объяснение:
Modal verb 'can'
Can is an auxiliary verb, a modal auxiliary verb. We use can to:
- talk about possibility and ability
- make requests
- ask for or give permission
The main verb is always the bare infinitive (infinitive without "to").
subject
auxiliary verb
main verb
+
I
can
play
tennis.
-
He
cannot/can't
play
tennis.
?
Can
you
play
tennis.
Modal verb 'must'
We often use must to say that something is essential or necessary, for example:
Must is a modal auxiliary verb. It is followed by a main verb.
subject
auxiliary verb
main verb
I
must
go
home.
You
must
visit
us.
We
must
stop
now.
In general, must expresses personal obligation. Must expresses what the speaker thinks is necessary. Must is subjective.
In each of the above cases, the "obligation" is the opinion or idea of the person speaking. In fact, it is not a real obligation. It is not imposed from outside.