2. Pay attention to this:
No change in form: no –s in 3rd person singular (except
“HAVE TO” or “BE ABLE TO”)
No “DO” in negatives or questions (except “HAVE TO”)
No infinitive
Followed by infinitive without “TO” (except OUGHT TO,
HAVE TO, USED TO)
3. ABILITY
Past Present Future
COULD
WAS ABLE TO
COULDN’T
CAN
CAN’T
WILL BE ABLE TO
WON’T BE ABLE TO
When I was a child I could
jump very high.
I was able to finish my task.
I couldn’t mend your bike.
She can speak 5 languages.
I can’t ride a horse.
I will be able to swim soon.
I won’t be able to come tomorrow.
5. PERMISSION
Past Present
COULD
WAS ALLOWED TO
COULDN’T
CAN / COULD
BE ALLOWED TO
MAY / MIGHT (formal)
CAN’T
When I was 16 I could go out at night.
She was allowed to stay out late.
I couldn’t go out yesterday. I was punished.
You can leave the room when you finish.
Could I ask you a question?
You are not allowed to smoke here.
May I come in?
Might I see the exam, sir?
She can’t go out until she finishes her tasks.
6. OBLIGATION
Past Present Future
HAD TO
DIDN’T HAVE TO
MUST
HAVE TO
HAVE GOT TO
(informal)
NEEDN’T
DON’T HAVE TO
WILL HAVE TO
WON’T HAVE TO
When I was a child I had
to work a lot.
Last year I didn’t have to
study so much.
You must get up earlier.
She has to work every day.
I’ve got to go. See you!
You needn’t come so early.
I don’t have to work on Sundays.
You will have to work hard there.
I won’t have to come tomorrow. It’s
Sunday.
7. PROHIBITION
Past Present
WASN’T TO
WASN’T ALLOWED TO
COULDN’T
MUSTN’T
ARE NOT ALLOWED TO
CAN’T
When I was a teenager, I wasn’t to come
home later than 10.
Some years ago women were not allowed to
vote.
During the war you couldn’t go out at night.
You mustn’t cross the street when the light is red.
You are not allowed to smoke in here.
Children can’t leave school until they are 16.
