Modal verbs express ideas like possibility, intention, obligation, advice and necessity. There are several modal verbs in English including can, could, may, might, must, should and have to. Modal verbs are used with other verbs to add abstract meanings and are always followed by a bare infinitive verb except for ought to. Each modal verb has specific meanings and uses related to ability, permission, certainty, advice and other concepts.

1. MODAL VERBS

2. Modal Verbs express ideas such as
Possibility, Intention, Obligation, Advice and
Necessity

3. MODAL AUXILIARY VERBS
DEFINITION
1. They are part of the verbal phrase:
I must get there before 7 o'clock.
2. They always accompany, assist or help
other verbs.
3. They add abstract (modal) meanings like
obligation, permission, advice, etc

4. LIST OF MODAL VERBS
can could
*be able to must
*have to need
should *ought to
may might

5. MODAL VERBS STRUCTURE
1. How do we use modal verbs?
Affirmative: subject + modal + infinitive
ex. She should stay
Negative: subject + modal(n't) + infinitive
ex: She shouldn't stay
Interrogative: (Wh)Modal + subject + inf.?
ex: Why should she stay?

6. 2. Modal verbs are used with infinitives
without to (bare infinitives) with the
exception of ought to:
We must get there before 7 o'clock.
She should study harder.
I ought to go home now.
(Have to is studied with modal verbs but it's
not a pure modal verb as it needs auxiliary
verbs and has -s in the third person
singular)

9. 6. Modal verbs do not have all the tenses.
They use other verbs to complete the
tenses:
can > could, be able to
They can swim now > She will be
able to swim next year
must > had to
You must come early > You had to
come early yesterday

10. MODAL VERBS
MEANINGS

11. Can/ Be able to / Can’t
 CAN
 Different uses:
 Abilities or capacities (to know or to
be able to).
 Mary can swim very fast.
 Request, ask or give permission
 Can you call me tonight.
 Possibility
I can meet you later.
 It can also be used for suggestions.
 You can eat ravioli if you like pasta.

12.  Be able to
 It expresses abilities like can and it is used
in all the verbal tenses where can is not
used.
 I was able to finish my homework on time
 Can’t
 Different uses:
 Lack of ability (not to know) or capacity (not to
be able to): I can’t eat a whole cake by myself
 Prohibition
 You can’t drive without a licence
 Disbelief
 That can’t be the price – it’s much too cheap.

13. Could
 It is the past of can and it is used to
express:
 Ability or capacity in the past
 She could run fast when she was a child
 Polite request
 Could you help me with these suitcases?
 Polite suggestion
 You could exercise and eat healthier food
 Possibility –less probable than with can-
 Mark could join us the cinema.

14. May/ might
 Both of them express possibility,
but might is more remote.
 It may/ might rain tomorrow
 In questions, may is the polite
way of asking for things.
 May I have a coffee, please?

15. Would
 In questions, it is a formal way
of asking for things.
 Would you open the window,
please?
 With the verb “like” is used to
make offers and invitations.
 Would you like something to
drink?

16. Must / Have to
 Both express obligation, but must is
only used in the present and have to
in the other tenses. Authority people
use must, while have to is used by
everybody.
 You must bring your books to class
 I have to buy the tickets today.
 Must is also used to express a
logical deduction about present fact.
 She’s got a great job. She must be very
happy.

17. Need to / Needn’t
 Need to is not a modal, but it is used
in affirmative sentences, like have to,
to express obligation and necessity.
 I need to cook dinner tonight.
 Needn’t, on the contrary, is a modal
and indicates lack of oblication and
necessity, like don’t have to
 You needn’t bring anything to the party.

18. Musn’t / Don’t have to
 Musn’t shows prohibition.
 You musn’t exceed the speed limit
 Don’t have to means not have
to, i.e., lack of obligation and
necessity, like needn’t
I don’t have to get up early
tomorrow

19. Should /Ought to
 Both of them express advise or
opinion, but should is used more
frequently, since ought to is
quite strange in negative and
interrogative.
 You should/ought to improve your
pronunciation

20. Shall
 It is used in the interrogative to
offer oneself to do something
and to make a suggestion.
 ShallI help you with your
luggage?

21. ABILITY REQUEST POSSIBILITY INABILITY
CAN Mary can swim very fast Can you call me tonight? I can meet you later
I was able to finish my
BE ABLE TO homework on time
I can't eat a whole cake
CAN'T by myself
She could run fast when Could you help me with Mark could join us at
COULD she was a child (past) the suitcases? (polite) the cinema
It may/might rain
MAY/MIGHT tomorrow
May I join this team?
MAY (polite)
Would you open the
WOULD window, please? (formal)
MUST
HAVE TO
NEED TO
NEEDN'T
DON'T HAVE TO
MUSTN'T
SHOULD /OUGHT
TO
SHALL

22. PROHIBITION DISBELIEF SUGGESTION/ OBLIGATION/
OFFER NECESSITY
CAN
BE ABLE TO
That can't be the
You can't drive price - it's much too
CAN'T without a licence cheap
You could exercise
COULD and eat healthier
food (plite)
MAY/MIGHT
MAY
Would you like
WOULD
something to drink?
MUST You must bring your
books to class
(strong)
HAVE TO
I have to buy the
tickets today
NEED TO
I need to cook
dinner tonight.
NEEDN'T
DON'T HAVE TO
MUSTN'T You musn't exceed
the speed limit
SHOULD /OUGHT TO
Shall I help you with
SHALL
your luggage?

23. CERTAINTY OF LACK OBLIGATION/ ADVICE/ OPINION
TRUE NECESSITY
CAN
BE ABLE TO
CAN'T
COULD
MAY/MIGHT
MAY
WOULD She's got a great
job. She must be
very happy.
MUST
HAVE TO
NEED TO
You needn't bring
NEEDN'T anything to the party
I don't have to get up
DON'T HAVE TO early tomorrow
MUSTN'T
SHOULD /OUGHT
You should/ ought to
TO improve your
pronunciation
SHALL

24. MODAL PERFECTS
 Must have + participle
 It expresses a logical conclusion
about a past fact.
 Rob has arrived late. He must have
been in a traffic jam.
 May/might have + participle
 We use it to make a supposition
about something in the past.
 She may/might have taken the wrong
bus.

25.  Could have + participle
 Ability to do something in the past
which in the end was not done
 You could have asked the doctor
before taking the medicine.
 Couldn’t have + participle
 Certainty that something did not
happen
 He couldn’t have gone to the concert
because he was doing the test.

26.  Would have + participle
 Desire to do something in the past which
in fact could not be done.
 I would have gone to the party, but I was too
busy.
 Should/ought to + participle
 Criticism or regret after an event
 You should/ought to have warned me earlier
 Shouldn’t have + participle
 Criticism or regret after an event,
showing that it shouldn’t have happened
 He shouldn’t have forgotten about her
birthday

27.  Needn’t have + participle
 An unnecessary past action
 You needn’t have brought anything to
my party.

28. Should /Had better
 Should/had better
 Had better is used in a more
colloquial way of expressing what
someone has to do, to give advise
or opinions.
 You’d better go to the doctor.
 It also it is used to express a
warning
 You’d better tidy your room now