1. MODAL VERBS
can- can’t
(be able to)
must- mustn’t
(have/has to)
(don’t/doesn’t have to)
could
should
ought to
2. 1. MODAL VERBS ARE NEVER USED WITH OTHER AUXILIARY VERBS
SUCH AS DO, DOES, DID ETC.
2.THE NEGATIVE IS FORMED SIMPLY BY ADDING "NOT" AFTER THE
VERB;
EX: YOU SHOULD NOT DO THAT.
QUESTIONS ARE FORMED BY INVERSION OF THE VERB AND SUBJECT:
EX: COULD YOU PICK ME UP WHEN I FINISH?
3.MODAL VERBS NEVER CHANGE FORM: YOU CAN NEVER ADD AN "-S"
OR "-ED", FOR EXAMPLE.
3. CAN – CAN’T
Many animals can see clearly in
the dark.Human beings can’t do this.
You can look at the animals in the
zoo but you can’t touch them.
I can attend that meeting next week.
But I’m not sure yet.
Possibility.
Permission ,what is allowed or
not allowed
Ability or lack of it
4. BE ABLE TO
• Be able to can be used instead of can. It has the
same meaning as can.
Ex: Many animals are able to see in the
dark.
• Be able to is used when can is unsuitable.
Ex: I haven’t been able to fınish my
project. I think I will be able to finish
it next month.
5. MUST – MUSTN’T – HAVE TO
DOES/DOESN’T HAVE TO
I must get enough sleep I want to
be active during the play.
High school students have to
wear uniforms at school.
University students don’ have to
wear uniforms.
It is military zone and you mustn’t
enter here.
Prohibition, actions against the
rules.
Match the sentences with the explanations.
Necessity, personal preference
Obligation , external obligation
No obligation, not necessary
6. HAD TO – DIDN’T HAVE TO
When we talk about past obligations and necessities,
we use had to.
Ex: In the past, women had to fight hard to get a place
at university.
To talk about the actions which were not necessary in
the past, we use didn’t have to.
Ex: You didn’t have to submit your project. It is
due next week.
7. SHOULD – OUGHT TO – HAD BETTER
Should , ought to and also had better are used to talk about
duty or to give advice
Ex: You should stop worrying about small problems.
Ex: You had better wear warm clothes. I think it’s going
to be cold. (Negative: You had better not + verb)
Ex: You ought to buy that shirt.
(Negative : You ought not to + verb)
8. COULD – COULDN’T – WAS/WERE ABLE TO
We use these structures to talk about past ability.
Frank Sinatra could sing well but he
couldn’t write his own songs.
(This is about ability.)
He tried hard but wasn’t able to finish the
race.
Women couldn’t compete or watch the
ancient Olympic Games.
(This is about permission.)
9. MAY – MIGHT - COULD
We use these modals to talk about uncertain situation or
for the things that will possibly happen.
Ex: The next earthquake may/might/could
happen any time tomorrow.
Ex: I may/might not come to the class
tomorrwo because I’m not feeling well.
10. REWRITE EXERCISE
(IN OTHER WORDS)
1. I suggest you to see that movie.
..............................................................................
2. It’s your duty to tidy this room.
(to)......................................................................
1.You should see that movie.
2.You ought to tidy your room
11. 1. It is not very probable that Ann will arrive from Brazil
before July.
................................................................................................
2. That’s top secret: You are not permitted to say
anything about it.
.........................................................................
Ann might not / may not arrive from Brazil before
July.
You mustn’t say anything about it. OR
You can’t say anyting about it.
12. It’s not necessary to clean the kitchen. I will do it later.
...................................................................................
You don’t have to clean the room.I ‘ll do it later.
Dogs are not allowed in the new restaurant by the river.
You.......................................................................
You mustn’t take your dogs into the restaurant by the
river.
13. As the president of the club, it was my duty to
organize the events.
.....................................................................................
As the president of the club, I had to organize the
events.
You are obliged to wear a helmet while you are driving a
motorbike
................................................................
You have to wear a helmet while you are driving a
motobike.
Editor's Notes
These are in parentheses as they are not actually modal verbs: be able to - have/has to – don’t/ doesn’t have to
Ought to has two words so it’s a little different from the other modals.
This is not the full list of modals (shall, may, might, will, would are missing; need could be added)
Had better is like a warning: You had better wear warm clothes (implies otherwise you will get ill).
was/were(n’t) able to implies something that was difficult.
could is not used for things that are only done once, as/were able to used for this
