2.  They are:
• Can
• Could They are Auxiliary verbs that
• Must provide additional and specific
meaning to the main verb of the
• Shall
sentence
• Need
• May
• Might Modal verbs are sometimes
• Should referred to as
Modal Auxiliary verbs because
• Will
they help other verbs
• Ought to

3. S M V
Subject Verb
Example: Mary could play the piano
They do not accept conjugation
They do not need other auxiliary verbs

4. There is no “s” in singular
There is no “do / does” in the question
There is no “don’t / doesn’t” in the negative
 He can ski.
He cans ski or He can skis
 Can he ski?
Does he can ski?
 They can’t ski.
They don’t can ski

5. Modal verbs do not have infinitives or –ing forms
to can / caning to must /musting
Modal verbs are followed by an infinitive without to
except for ought to
She must study
We should have gone the other way
He could play football in his youth
You ought to go to the gym more often

6. Modal verbs do not have all the tenses
Modal verbs use other verbs to complete the tenses
Can is completed with be able to
Must is completed with have to
You must come early They can play the piano
You had to come early yesterday They will be able to play the piano in the future

7.  They can have different meanings depending on the
situations they are used
 To understand it better we are going to divide them into 4
categories
1. Modal Verbs of obligation, no obligation, prohibition and
advice.
2. Modal verbs of ability and permission.
3. Modal verbs of speculation and deduction.
4. Modals perfects: They are used to express a situation in the
past

8. Obligation, no
obligation, prohi Ability and Speculation and Modal
bition and permission deduction perfects
advice
must/ may may/might have
mustn’t can / can’t
have to/don’t might / might should/
have to not shouldn’t have
needn’t could /
could must have
couldn’t
ought to
can’t can’t have
should/
shouldn’t may
must could have
can’t

9. Modal Concept Examples
*1 Must You must decide now.
Obligation
Have to/has to I have / she has to be fit to enter the race.
You don’t have / she doesn’t have to
*2 Don’t have No obligation
phone me tomorrow.
to/doesn’t have to (it’s not
You needn’t meet me at the airport. I’ll get
*3 Needn’t necessary)
a taxi.
They ought to thank her for the present.
Ought to
You should stop smoking all the time.
Should Advice and
You shouldn’t cross the street without
Shouldn’t recommendation
looking first. It’s dangerous.
Must
You must try this recipe.
You mustn’t ride a motorbike without a
Mustn’t
Prohibition helmet.
Can’t
You can’t park here – look at the sign.

10.  *1 In writing there is no real difference between these words. In speech
there is sometimes a small difference. Must is used when the speaker
personally feels something is important and have to is used when the
situation makes something necessary.
You must start working harder! (I say so)
You have to turn left here. (it’s the law)
 *2 Must and have to are very similar in their affirmative forms but they
are completely different in their negative forms. Mustn’t describes sth
which is prohibited. Don’t have to describes sth that is not necessary.
You mustn’t leave now. (it’s not allowed. It’s against the rules)
You don’t have to leave now. (it’s not necessary)
 *3 In informal spoken language we use don’t need to instead of needn’t.
You don’t need to go to the gym every day. You’re in good shape.

11. Modal Concept Examples
I can play the piano.
Can / can’t Ability in the present
My friend can’t speak Spanish
Could / He could ski when he was 4.
Ability in the past
couldn’t I couldn’t ride a bike when I was a child
Can To ask permission Dad, can I go to the concert?
Could and make polite Could I have some money, please?
May requests May I come in, please?
You can borrow this CD if you like.
Can Permission in the
Students can’t wear their own clothes to
Can’t present
school.
I could stay out until midnight when I
Could Permission in the
was 14.
Couldn’t past
We couldn’t wear jewellery at school.

12. Modal Concept Examples
*1 May He’s wearing a ring, so he may be
married.
Might
Speculation I might go shopping later, I don’t know.
Could
It could rain today.
Might not
She might not be on the train.
Can’t Negative deduction That can’t be Sue. She’s in Brazil.
Affirmative You must be tired after your long
Must
deduction journey.
*1 these words all express uncertainty or possibility. Could is not used with
not in this context.
The meaning for all three words is approximately 50% probability. But if we
stress the modal verb strongly in speech the probability is reduced.

13.  They are modals referred to actions that
happened in the past
MODAL + HAVE + verb in past participle
It must have been a difficult decision
They should have invited her to their wedding

14. Modal Concept Examples
Past unreal We may have passed the test, but it was
May have
possibility too difficult.
Past unreal small She might have been swimming. Her hair
Might have
possibility is wet.
You should have listened to the doctor.
Past unreal
Should have You shouldn’t have eaten too much
recommendation
chocolate.
Past unreal She looks very fit. She must have been to
Must have
assumption the gym a lot lately.
Impossibility in the He can’t have stolen the money. He was
Can’t have
past with me all morning.
Past unreal She could have taken the flight.
Could have
ability/possibility They could have won the match.

15. 1. My son ___ be home by now. Where can he be?
a. Have to b. Would c. Should d. Could
2. I think your thumb is broken. You ___ go to the emergency room.
a. Might b. could c. ought to d. can
3. If you are interested in losing weight, you ______ try this new diet.
a. Could b. mustn’t c. don’t have to d. had to
4. Johnnie’s fallen down the stairs! I ________ call an ambulance!
a. Will b. might c. may d. ought to
5. You _______ come too early. We won’t leave until 9 o’clock.
a. Has to b. must c. needn’t d. can’t

16. 6. Children ________ be accompanied by an adult at the zoo.
a. Ought to b. must c. would d. mustn’t
7. You _________ talk during tests. It’s forbidden!
a. don’t have to b. mustn’t c. couldn’t d. ought to
8. I can feel the heat. We _________ be near the fire.
a. Can b. would c. must d. have to
9. They ________ hear him because he was whispering.
a. Wouldn’t b. mustn’t c. shouldn’t d. couldn’t
10. You’ve never heard of Britney Spears! You ________ be serious!
a. Must b. had to c. can’t d. shouldn’t

17. 11. __________ you like to have dinner with me tonight?
a. Could b. may c. should d. would
12. You _________ let him hear about the party tomorrow. It’s a
surprise!
a. mustn’t b. wouldn’t c. couldn’t d. can
13. __________ I speak to the Chief of Police, please?
a. Must b. May c. Would d. Need
14. He has arrived late. He _______ missed the bus
a. Must have b. Should have c. Could have d. must

18.  Re-write the following sentences using modals so that they have the
same meaning.
1. I suggest that you get a good lawyer!
should get a lawyer
You ___________________________________________
2. A university degree isn’t necessary for that job.
needn’t have a university degree for that job
You ___________________________________________
don’t have to have a university…
3. Perhaps my father will pick you up.
may / might pick you up
My father _______________________________________
4. 4. Eating is forbidden in class!
mustn’t eat in class
You ___________________________________________

19.  Re-write the following sentences using modals so that thay have the
same meaning.
5. Look at his dirty clothes! I’m sure he is a poor person.
must be a poor person
He ____________________________________________
6. I don’t believe that the legend of Hercules is true because there’re many
contradictions.
can’t be true
The legend of Hercules ____________________________

20.  Think about these situations and create a sentence using modals.
1. We are going to Paris for a weekend. (Make suggestions about things to
do)
2. We start school in September. (Talk about necessity)
3. Margaret is a very talented sportswoman. (Talk about ability)
4. You have just won the lottery! (Talk about possibility)
5. Peter has got a headache and a congested nose. (Give him some advice)
6. You want to borrow your uncle’s Mercedes Benz. (Ask for permission
politely)

21. 1. We could visit the Louvre / We should go up the Eiffel Tower
2. We have to buy a new notebook
3. She can speak 3 languages! / She is able to play the piano and the violin
4. I might stop working / I may buy a new car / I can travel to New York
5. You should see a doctor / You ought to drink hot tea
6. Can I borrow your car, please? or May I borrow your car, please?