This document discusses modal verbs and their uses for expressing ability, possibility, and alternatives. It begins by listing the twelve modal verbs in English and noting that their form does not change. It then explores how each modal verb is used to indicate ability in the present, past, future, and with passive constructions. Next, it examines how modals like must, may, might express different degrees of possibility in the present, past and future. Finally, it provides some alternatives to modals, like adverbs probably and possibly, to convey similar meanings.

2. Outline
Ability
Possibility
Alternative

3. Form
There are twelve modal verbs:
Modal verbs are follow by the infinitive without to, and their
form doesn’t change:
He could speak French. (not He coulds speak French.)
Could you speak French? (not Did you could speak French?)
Can shall must
Could should ought to
May will need (to)
Might would dare

4. Ability
We use the following verbs to talk about ability
Present can, can’t, be able
to, manage to
I can not swim.
Past could, could not, be
able to, manage to
They were not able to find
out his name.
Perfect be able to, manage
to
Have you managed to finish
the report yet?
Future Be able to, manage
to
I won’t be able to meet you
later.

5. Ability
1. We use can/could to talk about general ability in the
present and past.
EX: She can speak Spanish.
2. If the present ability is surprising or involves overcoming
some difficulty, we can also use be able to:
EX: Despite he is handicap he is able to drive a car.

6. Ability
We cannot usually use be able to with a passive.
EX: This book is able to be used by students.
3. To emphasize the difficulty or to suggest a great effort
(the present, past, or future), we use manage to. In more
formal English we can use succeed in + -ing form:
EX: She will manage to get the a visa.
She succeed in getting a visa.

7. Ability
4. We use will be able to, not can to describe about a
future ability.
EX: Will I be able to join the meeting tomorrow?
5. We use could/might have + past participle to describe a
past opportunity which wasn’t taken.
EX: She could have helped him. ( She didn’t help him.)

8. Other uses of can
1. Can also means sometimes:
EX: I can play guitar. (I sometime play guitar.)
2. We use can to ask for and give permission:
EX: Can I love you?

9. Possibility
1. We use must, may, might, could, couldn’t, and can’t
when there is more information, evidence, or belief that
something is probably or possibly true or not true.
Very likely must
Possible Might, may, could, may not,
might not.
Very
unlikely
Can’t, couldn’t

10. Possibility
2. Could, may, and might express the same degree of
possibility. (The meaning is similar to ‘perhaps’ or ‘may
be’)
EX: She could/ may/ might remember some things already.
3. Couldn’t expresses the same probability as can’t. It is
usually used to talk about the past.
EX: The teacher knew he couldn’t do the test.
(He rarely join the class.)

11. Possibility
4. We use can to describe things which are generally
possible.
EX: Stays in 5 stars hotel can be very expensive.
(Stays are sometime expensive.)
5. We use well after may, might, and could if we think the
possibility is quite strong.
EX: Don’t worry, the contract could well be in the post.
(It is probably in the post.)
We use must if we are very certain of the possibility.

12. Possibility
PRESENT
We use may (not), might (not), could (not), must, can’t +
bare infinitive to talk about possibility in the present.
EX: He may eat cake already.

13. Possibility
PRESENT
We use may (not), might (not), could (not), must, can’t be+
+ -ing to talk about things (possibly) happening or in the
progress at the time of speaking.
EX: He must be having lunch.

14. Possibility
PAST
We use may (not), might (not), could (not), must, can’t +
have + past participle to talk about possibility in the past.
EX: When I entered the class, all
students must have been bored.

15. PAST
• We use may (not), might (not), could (not), must, can’t +
have been + -ing to talk about possibility happening in the
past.
EX: My My might have been
trying to fix the bike.
Possibility

16. Possibility
FUTURE
• We can use may (not), might (not), and could (not) +
infinitive without to to talk about possibility or uncertainty in
the future.
EX: We could love each other
one day.

17. Alternatives to modals
Adverbs like certainly, probably, possibly, perhaps and
maybe can be used to express similar ideas to modal verbs:
EX: Jam is probably missing
someone. (He must be missing)

18. Reference
Mark Foley & Diane Hall (2003).
Longman Advanced Learners’
Grammar (pp. 174-177).
Diana Hopkins with Pauline Cullen
(2009). Cambridge University. (pp.
107-113)

19. THE END
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