9. Modal verbs
• 1. How do we use modal verbs ?
Affirmative (+): S + Modal + V
She can swim
Negative(-): S + Modal(n’t or not) + V
She can’t swim
Interrogative(?): (Wh) modal + S + V ?
Why can she swim?
Can I sing?
10. Modal verbs
• 2. Modal verbs are used with infinitves
without “to”(bare infinitives) with
exception of “ought to”
• Example: We should study harder.
I ought to go home now
Notice: Have to is studied with
modal verb but it’s not pure modal
verbs as it needs auxiliary verbs
and has –s in the third person
11. Modal verbs
• 3. Modal verbs do not add –s or –es
the third singular. They are invariable
• Example: He can sing
but: He cans sing
• 4. They don not have infinitives or –ing
• Example : canning – oughting to
12. Modal verbs
• They don’t need auxiliaries
short answers or negative and
Example :She shouldn’t eat it
She doesn’t should eat it
Example: May I help you? – Yes,
Do I may help you? – yes, you do
13. Groups of modal verbs
We are going to study them from two
points of view:
Numbers of meanings or concepts that they
express: single, double
Modal meanings that they express: ability,
15. Ability: can, could, be
• Present: can
Example: I can ski
Negative form: can’t
Example: I can’t ski
Interrogative: Can I ski?
16. Ability: can, could, be
• Past: Could :To
express general ability in the
When he was a child, he could ski well
17. Ability: can, could, be
• Be able to: semi-modal verbs
(1)use instead of “can”
(2)use in all the tenses
Example: (1)I am able to play the piano
(2) When he was child, he was
able to ski well
(2) Next week,they’ll be able to
(3) The bus was full but he was
able to find a good seat.
19. Obligation: must, have to
• The other
You must be at home at
10 o’clock(I insist)
You must get up early in
the morning (I say so)
I must be at home at 10
o’clock (my parents
You have to turn left
here ( it’s law)
20. Obligation: must, have to
• Must have no past form
sorry I am
• Example I had
Did I have
to take the to
21. Obligation: must, have to
Have to: semi- modal verbs
use in all tenses
o Example: I hate having to get up early
I hate musting get up early
Notice: use auxiliary verbs (do/ does/ did) in
negative form and interrogative form
o Example: What time do you have to start work?
We don’t have to study
Did you have to walk home last night?
22. Obligation: mustn’t, don’t have to
Don’t have to
• Describe something is
• Describe something is
You mustn’t wash
that sweater. It is
has to be dry
have to get
should, ought to
• Express advice and recommendation
o Example: Candidates should be friendly
= Candidates ought to be friendly
Negative: Candidates shouldn’t be friendly
25. Possibility: can, may, might, could
• Can happen in the present and future
Ex1: There’s someone at the door. It’s may be
Ex2: We aren’t sure where we are going to
tomorrow. We might go to the beach (=
perhaps we go to the beach)
26. Possibility: can, may, might, could
Negative form: may not, might not
Don’t use could not
• Example: Simon may not at home.
We might not go to the beach.
27. Deduction:must, can’t
Give a predict certainly
• It’s not very warm and you
are not wearing a coat. You
must be cold.
(= I am sure that you are cold).
Use in affirmation
Give predict that don’t
• Peter was here a moment
ago, so he can’t be far away.
(=It’s possible that he is far
Use in negative
29. Request: can, could, may, will,
Can &could: make a request
• Form: Can/could + S + V
Can: is used to make a basic
o Can I open the door?
• Could: is more polite and formal
but the same function
o Could you turn off the radio?
30. Request: can, could, may, will, would
May is more formal than could and can
• Example:May I know your name, sir?
May, can , could is used much more polite
than imperative command
• Ex: Open the door -> Can you open the door?
Turn off the radio -> Could you turn off the
31. Request: can, could, may, will, would
Will & would
• Will: use to ask sb to do st
o Example: Will you switch on the light, please?
• Would is used more polite than will but it is less
o Example: Would you post this letter for me?
Would always accompany with mind to give a
o Example: Would you mind switching off the light?
33. Offers: can , could, will, shall,
Will:willing to do st or propose to do st
• Ex: I’ll help you with your suitcase.
Can &could: (Ability) to offer to do st for sb
• Ex: I can post this letter for you?
I could lend you some money if you want.
34. Offers: can
, could, will, shall, would
Sometimes use Can or could to permit but
actually we are propose ourselves to do st.
Can I make
you cake to
35. Offers: can , could, will, shall,
Sometimes use Can or could to
permit but actually we are
propose ourselves to do st.
36. Offers: can
, could, will, shall, would
Would accompany with Like, Prefer, Rather to
give the propose and invite provel
• Ex: Would you like to go to a party on
• Ex 2: Would you like me to help you?
• Ex 3: Would you prefer to stay in or go out this
• Ex 4: Would you rather stay in or go out this
41. Could have
We use could have + Past participle to:
Show we had the ability to or the opportunity
to do st in the past but we did not do it
• Ex: You could have helped me. Why didn’t
Show the action that almost happen but didn’t
• Ex: Be careful! The car could have knocked you
Express a weak possibility in the past
• Ex: I don’t know where I lost my umbrella. I
might have left it on the train. I might have
dropped it. Or I might have left it at the shop. I
really don’t know
43. Must have
Show we are almost sure something happened
in the past (past logical conclusion)
• A: John was terribly tried yesterday and when
I called him last night, he didn’t answer the
• B: He must have fallen asleep
44. should have/ shouldn’t have + P
Talk about unfulfilled obligation in the past
• Ex: You should have returned the book to the
library on time. Now you have to pay for fine.
Talk about regrets
• Ex: You should have let your daughter marry
the man she loved. She’s so unhappy now.
• Ex: You shouldn’t have spoiled your son like
this. Now he is out of control
45. Needn't have
• Needn't have + past participle : to talk
about an action which was done but which
• Ex1: I needn't have made so much food for the
party. Nobody was very hurry.