Modal verbs are used to express ideas like possibility, willingness, ability, obligation, certainty and permission. Some common modal verbs include can, could, may, might, will, would, shall, should, ought to, must and have to. Modal verbs are used with other verbs and have consistent forms across subjects. They are used to talk about present and past ability, permission, obligation, advice, possibility, probability and requests.

1. Modal Verbs
or
Modal Auxiliary
Verbs

2. Modal Verbs
We have lots of “modal verbs”, such as:
 Can  Shall
 Could  Should
 May  Ought to
 Might  Must
 Will  Need
 Would  Dare

3. USE of Modal Verbs
 We use modal verbs to talk about possibility,
willingness, ability, obligation, certainty and
permission.
 Examples:
It might rain. (possibility)
Will you help me?(willingness)
Can she swim? (ability)
You must be home by 11 o’clock. (obligation)
You haven’t eaten all day. You must be hungry.
(centainty)
May I borrow your car? (permission)

4. FORM of Modal Verbs
 We form the affirmative by putting the modal verb
between the subject and the full verb.
“We should go”
Subject (or pronoun) + Modal verb + Verb
 Modal verbs take the same form in all pronouns. The
verb doesn’t change after modal verb.
“We should goes”
“We should going”
“We should went”
“We should to go”

5. FORM of Modal Verbs
 NEGATIVE FORM: We form the negative by
putting “not” after the modal verb.
“She can’t swim”
“It might not rain”
 INTERROGATIVE FORM: We form questions
by inverting the subject and the modal verb.
She can swim. Can she swim?
We should go. Should we go?

6. Ability
CAN COULD BE ABLE TO
Expresses Expresses Expresses general
general ability in general ability in ability in the past
the present. the past. and in the present.
It means “Puedo” It means “Pude” It means “Tengo o
tuve la habilidad
de…”
“I was / am
“I can play the “I could play
guitar” the guitar” able to play the

7. Permission
CAN COULD MAY MIGHT
Is the most Is less direct More formal Less direct
common. and polite than than can or and formal
can could
It gives General It gives
permission permission to permission
do something
in the past

8. Obligation and Necessity
MUST HAVE TO
We use must when the We use have to when the
authority comes from the autthority comes from
speaker. outside the speaker.
It is used in the present and Used in the past (Had to)
in the future
QUESTIONS: Use of
“You must be home by 10 do/does in present simple
o’clock” and did in the past.
“I have to be home by 10”

9. Obligation and Necessity
DON’T DON’T
MUSTN’T HAVE TO NEED TO NEEDN’T
Obligation Is not It is not It is not
not to do necessary to necessary to necessary to
something do do do
something something something
You musn’t I don’t I don’t I needn’t
smoke in a have to get need to get get up today.
hospital up today. up. I’m on
holiday.

10. Obligation and Advice
SHOULD OUGHT HAD SHALL
TO BETTER
Obligation and Obligation Expresses a We use it
duty and duty strong when we
Ask for and give (laws or recommendation want to know
advice rules) in a particular someone’s
situation. opinion, or
Say what is right Ask for and
give advice Present or when we
or wrong
Say what is future, not past. want advice
right or wrong or

11. Possibility
MAY MIGHT COULD
Used in present Used in present Used in present or
or future or future future
+++May ++Might +Could
It doesn’t express
posibility in
negative
“There is “We might go to “Where is Simon?”
someone at the the beach” “He could be in
door, it may be the living room”

12. Probability
SHOULD OUGHT TO
It is used to say that It is used to say that
something is probable at something is probable at
the moment of speaking, or the moment of speaking, or
in the future. in the future.
“Sally should be at work “He ought to pass his
by now.” driving test easily.”

13. Request
CAN COULD MAY WILL WOULD
It is used to It is used to It is used to We use it to We use it to
ask for ask for ask for ask someone ask someone
something something something to do to do
Less Direct The most something for something for
and more formal us. us, but is
polite more polite.
It is used to It is used to It is used to Would like:
ask for ask for ask for Polite way of
permission permission permission saying what
and to ask and to ask we want.
someone to someone to “I would like
do something do something a glass of
for us. for us, but is water, please”

14. Offers
Will Shall Can Could Would
It is used to Shall I? is It is used to It is used to It is used with
say that we used to offer offer to do offer to do like, prefer
are willing to to do something for something for and rather, to
do something something for someone. someone. make polite
or to offer to someone. Is more polite offers and
do something. and less invitations.
direct.
I will help you Shall I help I can send I could lend Would you
with your you? this letter for you money if like to go to a
suitcase. you. you want. party on
Saturday?