This document provides information about modal verbs in English and examples of their uses to express different meanings such as advice, permission, obligation, absence of obligation, ability, possibility, and prohibition. It defines modal verbs as special verbs that do not take an "s" in the third person singular and are followed by an infinitive without "to." The document then gives examples of modal verbs used to express different meanings in sentences and questions. It provides a chart with modal verbs and their uses to express various meanings like advice, permission, obligation, etc. There are also exercises asking to complete sentences using the appropriate modal verbs.

1. IES PEÑALBA UNIT 8 3º ESO
Modal verbs are special verbs that:
- Have the same form for all persons (they don’t take “-s” in the 3rd person singular).
- Are followed by an infinitive without TO (except for have to and ought to).
- Use "not" to make its negative (except for have to).
- Change the order with the subject to form interrogatives (except for have to).
EXPRESSING ADVICE
SHOULD You should /ought to take a taxi home. It’s raining.
OUGHT TO You shouldn’t /oughtn’t to walk home. It’s raining.
Should we take a taxi home?
EXPRESSING PERMISSION
CAN (informal): Can I open the window?
COULD (more polite): Could I open the window? Asking for permission
MAY (formal): May I open the window?
CAN: You can have one more if you want. Giving permission
CAN’T: You can’t enter this room. Refusing permission
EXPRESSING OBLIGATION / NECESSITY
MUST (strong obligations/rules or personal feelings) You must follow the school rules.(I’m obliged)
I must see a doctor soon. (I decide it’s necessary)
HAVE TO (external obligation) I have to do my homework every day (Others decide it’s necessary)
 Must is the Present Simple form. It borrows its interrogative form and the rest of its tenses
from the verb have to.
I had to go to the supermarket yesterday.
Do you have to wear a uniform at school?
EXPRESSING ABSENCE OF OBLIGATION / PROHIBITION
MUSTN’T (prohibition) You mustn’t park here. (It’s forbidden)
DON’T HAVE TO (It is not necessary) You don’t have to do it now. You can do it later.
(You don’t need to)
EXPRESSING ABILITY
CAN (ability in the present or future) Can you swim? No, I can’t but I can run fast.
COULD (ability in the past) She could read when she was three.
EXPRESSING POSSIBILITY / PROBABILITY
MUST (it is almost certain) They look alike. They must be twins.
MAY (It is very possible) I may go to the cinema next weekend.
COULD (it is possible) Look at the clouds. It could rain in the afternoon.
CAN’T ( It’s impossible) You have been sleeping all day. You can’t be tired.

2. IES PEÑALBA UNIT 8 3º ESO
1. Give advice with the expressions from the box. Use you, he, she, we, they and should
/ought to or shouldn’t/oughtn’t to.
take medicine / take up swimming / worry about it / eat so much sweets / do little jobs or go babysitting /ask your
teacher to explain it again / study harder / watch too much television / practise a lot / get up earlier
1. We are often late for school.
_____________________________________________________________________________
2. My friends laugh at me because I don’t have expensive clothes.
_____________________________________________________________________________
3. My mother has got a terrible headache.
_____________________________________________________________________________
4. I don’t understand how to give advice in English.
_____________________________________________________________________________
5. My brother gets very bad marks at school.
_____________________________________________________________________________
6. We’re going to take a Maths test tomorrow.
_____________________________________________________________________________
7. My sister can’t swim and she wants to go to Greece next summer.
_____________________________________________________________________________
8. I am not very god at playing the guitar.
_____________________________________________________________________________
9. My friends love eating and they’re very fat.
_____________________________________________________________________________
10. I want to buy some new clothes but I haven’t got any money.
_____________________________________________________________________________
2. Complete the rules at the community centre swimming pool. Use must, mustn’t or don’t have
to.
1. You …………………………. walk slowly around the pool area.
2. You …………………………. eat near the pool.
3. You …………………………. have a shower before you enter the pool.
4. You …………………………. take any swimming courses.
5. People with long hair …………………………. wear a bathing cap.
3. Fill in the gaps with must, have to, mustn’t or don’t have to.
1. My father work at an office and he ________________ wear a tie every day.
2. If you want to park here, you ________________ buy a ticket.
3. You ________________ shout at your parents.
4. You ________________ shout, I can hear you.
5. __________ I ___________ go to bed early? Yes, you ____________
6. You ________________ take photographs in any museum.
7. We ________________ study hard if we want to pass our exams.
8. She ________________ go to Barcelona next week.
9. You ________________ use your phone in class.
10. My sister ________________give me her phone. I have already found mine.
4. Fill in the gaps with can / can’t / could or couldn’t.
1. Last week, I was ill and I ___________ get out of bed.
2. My brother is very athletic. He ___________ ride a skateboard when he was three.
3. Miranda is very shy. She ___________ talk in front of a big audience.
4. Frank is very funny. He ___________ make anyone laugh.
5. Shelly ___________ ride a bike last year, but now she rides well.
6. Eric has travelled a lot. He ___________ speak three languages.

3. IES PEÑALBA UNIT 8 3º ESO
7. Nicole ___________ drive, but she doesn’t have a car.
8. We ___________ see the sea from our hotel window. It was too far.
9. ___________ you walk when you were eleven months old?
10. Where is my mobile phone charger? I ___________ find it.
11. They ___________play football yesterday because it was raining.
12. I don’t understand the homework. ___________ you help me?
13. ___________people take photos with telephones 50 years ago? No, they___________
14. My mobile phone isn’t working. ___________ I use yours?
15. Eric ___________buy an iPnone because he didn’t have enough money.
5. Complete the sentences with must or can’t.
1. How can you say that? You ____________ be joking!... You ____________ be serious!
2. Their car isn’t outside their house. They ____________ be at work.
3. That restaurant ____________be very good because it is always full of people.
4. John ____________ be hungry again. He has just had breakfast!
5. I bought the box of cereal yesterday. It ____________ be empty!
6. She ____________ be bored with her job. She always does the same thing!
7. That teacher has taught here for ages. He ____________ know the names of all the
students in the school!
8. He ____________ be Sara’s best friend because he hasn’t visited her in the hospital.
9. You passed all your exams, so you ____________ be really happy!
10. He has been running for two hours. He ____________ be very tired.
6. Fill in the gaps with must, may, could or can’t.
Dear “Unhappy”,
You 1._____________ be serious about leaving home! There 2. _____________be some
problems in your family, but there 3. _____________ be another solution. You should try
talking to a friend or a relative. You 4._____________ have some aunts or cousins who can
help. You 5. _____________find that discussing the problem all together is better. Your
parents 6. _____________be as angry as you think because they are your parents and they
love you; they 7. _____________ be upset but after you talk to them they will realize why
you’re so unhappy. I suggest you try talking to them again – you 8. _____________ be
surprised.
7. Choose the correct answer.
1. Ruth has got clever ideas. Mike should/must/doesn’t have to ask her for help with his
project.
2. Fred is very rich. He could / can / has to buy almost anything he wants.
3. There’s a terrible storm outside. You have to/don’t have to/mustn’t go out. It’s dangerous.
4. You can / should / could write when you were three years old.
5. I can’t find my wallet, so I can’t / must / shouldn’t go to the bank to get some money.
6. You mustn’t /must/ don’t have to use your phone in class.
7. You should / don’t have to / have to use your phone in emergencies.
8. You can’t / mustn’t / don’t have to go to the grocery. I have already gone.
9. You have to/ mustn’t /don’t have to call me and I’ll know you are safe.
10. Drivers oughtn’t to / don’t have to / mustn’t talk on their phones while they are diving.
11. She looks tired. She can / has to / should take some days off.
12. You must / mustn’t / have to get your mobile phone wet. That will damage it.
13. Could / should / can most people in your country read and write today?
14. We can/ must / ought to wear a helmet when we ride a motorbike.
15. You have to/ mustn’t / don’t have to sleep on the sofa. We have an extra room.