This document discusses the use of modal verbs to express ability, obligation, prohibition, necessity, advice, possibility, certainty, and obligation in the past tense. It provides examples of how to use modal verbs such as "can, could, be able to, must, have to, mustn't/must not, don't have to, need to, should, ought to, shouldn't/ought not to, might, may, could, must, can't, had to" in various contexts. It concludes by providing a practice section with blanks to be filled in using the appropriate modal verbs.

1. Modal Verbs

2. Ability
Can: Ability in the present
- I can swim faster than you.
Could: Abilty in the past
- I couldn’t speak English fluently when I
was your age.
- I was able to…
Will be able to: Ability in the future
- In ten years time, I will be able to speak
English fluently.

3. Obligation
Must: An obligation in the
present
(myself) or (authority).
-I must get down to work so I can’t
go with you to the birthday party.
Have to: General rules.
-You have to wear uniform in this
school

4. Prohibition
Mustn’t/ must not: You are not
allowed to do sth.
-You mustn’t smoke in class. It is
forbidden.
- You mustn’t speak in such way to your
mum. She cares about you.

5. No obligation
• Don’t have to/ doesn’t have to : It is
not necessary.
- You don’t have to get up early on a
Saturday. You can stay in bed a bit
longer if you want to as there is no class.

6. Necessity
Need to: Necessity in the present.
- I need to go through my notes again. I
need to memorise the definitions.
Don’t need to/ doesn’t need to:
(It is not necessary)
- You don’t need to bring any food to
the party. I will invite you all.

7. Advice
Should: To give advice to someone.
- You should think twice before making
such a difficult decision.
Ought to: ( to give advice formally)
-” You ought to revise the account of the
company” - The director said.

8. Advice
Shouldn’t / Ought not to :
-You shouldn’t take these pills without the
doctor’s supervision.

9. Possibility
Might: (Hypothetical possibility)
- She might take up salsa lessons if she
found a partner.
May: (+ likely to happen)
- She may come to the party if she finishes
her task.
Could: Possibility
- She could become a singer if she
practises a lot.

10. Certainty
MUST: To express that you are sure
about something.
- It must be very cold outside. Everyone
is wrapped up warm.
- She must be her mother. They look
very similar.

11. Certainty
CAN’T: You’re sure about something
which is impossible.
- It can’t be true. She told me a
different
thing!
- She can’t be her mother. She is very
young!

12. Obligation in the past
HAD TO: To express an obligation in the
past
- I had to finish my task for Friday so I
wasn’t able to go to the party.

13. Practice
Complete the following sentences using the modal verbs:
ability, obligation, permission, advice. (in present, past
and future tense. Negative sentences can also be provided)
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I really ________ go to doctor’s. I haven’t been for more than
two years and I’ve got a terrible toothache.
You ____________ get up early on Saturdays. Theres’s no
school.
I think you ______talk to her. She is your best friend.
You _____get a good night’s sleep before the exam.
She said I _______go to the supermarket and I forgot.
________ I talk to you for a second?
In ten year’s time you ____________________ to speak english
fluently.
You ____________ take pills without the doctor’s advice.