Modal verbs and phrases - Can / Could / be able to

Use of modal verbs and examples

1. Can, Could, Be able to
modals

2. You use CAN to
describe an ability in
the present.
Annie can swim, but
she can't ride a bike.
I can play the guitar
and sing.
You can also use BE
ABLE TOtodescribe an
ability in the present.
He's able to park a car,
but he's not able to
drive in traffic yet.
He’s crazy. He thinks
he is able to stop time
with his mind.

3. You use CAN to
describe an ability in
the present.
Annie can swim, but
she can't ride a bike.
I can play the guitar
and sing.
You can also use BE
ABLE TOtodescribe an
ability in the present.
He's able to park a car,
but he's not able to
drive in traffic yet.
He’s crazy. He thinks
he is able to stop time
with his mind.
In the PRESENT, the only difference between CAN and
BE ABLE TO, is that CAN is more common and BE
ABLE TO is more formal.

4. use COULD to describe a
general ability in the past.
My father could speak
five languages.
He was a very good
tennis player. He could
beat anybody.
use WAS/ WERE ABLE TO
if you are talking about
what happened in a
particular situation.
Jack and John played a
tennis match yesterday
and John was able to
beat Jack.
There was a fire, but we
were able to scape.

5. But in the negatiave, you can use COULDN’T in both
cases:
My father couldn’t
swim.
I couldn’t read when
I was 5.
There was a big fire
and some people
coulnd’t escape.
Yesterday Jack
couldn’t beat John.

6. For forms and tenses other than present or past, you
have to use BE ABLE TO.
We haven't been able to play tennis for a long
time. (Present Perfect)
I won’t be able to be there tomorrow.
(Future)
I’ve always wanted to be able to dance. (To-
infinitive)
etc.