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:
Structure of Be able to
The structure of be able to is:
subject + be + able + infinitive
| |
subject |
be
main verb |
able
adjective |
infinitive |
| + |
I |
am |
able |
to drive. |
| - |
She |
is not |
able |
to drive. |
| isn't |
| ? |
Are |
you |
able |
to drive? |
Notice that be able to is possible in all tenses, for
example:
- I was able to drive...
- I will be able to drive...
- I have been able to drive...
Notice too that be able to has an infinitive form:
- I would like to be able to speak Chinese.
Use of Be able to
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. Look at these examples:
- I have been able to swim since I was five. (present
perfect)
- You will be able to speak perfect English very soon.
(future simple)
- I would like to be able to fly an airplane.
(infinitive)
| EnglishClub.com Tip |
| Be able to is
not a modal auxiliary verb. We include it here for convenience, because
it is often used like "can" and "could", which are modal auxiliary
verbs. |
Now check your understanding
>> |
