This document discusses modal verbs, their uses, and rules in various contexts such as ability, permission, obligation, and advice. It covers the distinctions between different modals like can, could, may, must, should, and their perfect forms for expressing past actions or deductions. Additionally, it highlights grammatical structures and examples associated with each modal verb to clarify their usage.

1. MODAL VERBS
UNIT 2 – OUT AND ABOUT

2. MODAL VERBS
can ■ could ■ may ■ might
■ must ■ mustn’t ■ needn’t
■ should ■ ought to ■ will
■ would ■ shall
(have to ■ be able to ■ be allowed to ■
manage)

3. GENERAL FEATURES
• They always go before a verb in the INFINITIVE
He can swim I ought to study more He may have left
• They NEVER change, they don’t add –s or – ing
She must be mad! Félix should be revising
• In the NEGATIVE, they are always followed by NOT
CAN’T MAY NOT WON’T COULDN’T WOULDN’T MIGHT NOT ….
• In QUESTIONS, they go immediately before the subject, they don’t need
auxiliaries like don’t / doesn’t / didn’t /
May I go? Shall we stay with you? Will you marry me?
• They don’t have infinitive , gerund, participle… so they use other verbs
like: have to , be able to…
I can’t swim now, but next year I’ll be able to swim
They had to leave early to avoid the road congestion.

4. CAN, COULD, BE ABLE TO, MAY ,MIGHT
• POSSIBILITY: can, could, may, might
Accidents can happen
This year we can ski because it has been snowing a lot lately.
I can come and see you tomorrow if you like.
The word “play” can be a noun or a verb.
You can’t buy fruit now. The shops are closed. (impossibility)
We could see the beach from our hotel window.
**Could is only used in the affirmative with this meaning.
• MAY and MIGHT express possibility in the present or future. The only
difference is that MIGHT means the possibility is smaller. The best
translations are: puede que / quizás / pudiera ser que... You can also use them
in the negative.
He may invite us to his party, but I’m not completely sure.
They might win the match, although the difference is small.
He may not be ready.
They might not be interested in our proposal.
• Use might when the situation is not real.
If I were in Tom’s position, I might look for another job (may is incorrect here)

5. CAN,COULD,BEABLETO, MAY,BEALLOWEDTO
• PERMISSION: can, could, be able to, may, be allowed to
May is the most formal word
I haven’t got a pen - you can use mine
Could I open the window, please? (it refers to the present, not past!)
May I sit down here?
Can you go to the party tomorrow? No, we’re not allowed to go, my dad said so
When I was at school, we weren’t allowed to use pencil in exams.
*** We can also use «must /mustn’t» to express permission or lack of it
= (not) allowed to.
You must keep it a secret – you mustn’t tell anyone at all (=you aren’t allowed to
tell anyone)

6. CAN, COULD, BE ABLE TO, MANAGE TO
• ABILITY: can, could, be able to, manage to
• In the present: can - am/is/are/able to
• In the past: could - was/were able to - managed to
Helen could play the piano when she was younger, but she can’t play any more.
Now, she’s able to play the violin.
Julia managed to reduce her carbon footprint by half last year.
**DIFFERENCE COULD WAS/WERE ABLE TO (affirmative)
• Could is used for general ability in the past.
Mike was an excellent player when he was younger. He could beat anybody.
• If you want to say that somebody did something in a specific
situation, use was / were able to or managed to
The fire spread through the building but everybody was able to escape
(=managed to escape)
• In the negative, both couldn’t – wasn’t/weren’t able to are possible

7. BE ABLE TO - CAN
• Be able to is used in ALL TENSES, but sometimes can is better,
because it is more usual and be able to sounds very formal.
We are able to see the lake from the youth hostel.(it is correct, but «can» is better)
*** However, can has only two forms: present (can) and past (could). So
sometimes it is necessary to use be able to.
I haven’t been able to sleep recently. (present perfect)
Applicants for the job must be able to speak two languages.(infinitive)
I don’t think I’ll be able to phone you from the Everest!
►Attention! Don’t use be able to:
• To refer to something happening as we speak:
Listen to me! I can play this song on the piano now!
• Before passive structures.
More local food can be produced.
• When we mean «know how to» I can drive a car

8. Is could the past of can?????
• Not always. (Could you pass me the salt, please? Refers to the present)
• We use could especially with verbs like the following:
see - hear – smell – taste – feel – remember – understand
As soon as I walked into the kitchen, I could smell gas.
I was sitting at the back of the theatre and couldn’t hear very well.
• To say that somebody had the general ability of permission.
My grandfather could speak five languages.
We were totally free. We could do what we wanted. (=were allowed to)
• To talk about possible actions now or in the future (suggestions)
What shall we do this evening? We could go to the cinema. (also can + sure)
• To say: something is possible now or in the future (may/might)
The story could be true, but I don’t think it is (can is incorrect here)
• For actions that are not realistic.
I’m so tired, I could sleep for a week.

9. MUST and CAN’T for deduction
• Use must to say that you believe something is certain.
You’ve been travelling all day. You must be tired.
Lidia is a hard worker – Lidia? You must be joking, she’s very lazy!
• Use can’t to say that you infer something is not possible.
You ‘ve just had lunch. You can’t be hungry already.
They haven’t lived her for very long. They can’t know many people.
****Both forms exist in the past: MUST HAVE DONE / CAN’T HAVE DONE
I didn’t hear the phone. I must have been asleep.
Ignacio hasn’t contacted me. He can’t have got my message.

10. OBLIGATION: MUST, HAVE TO
• Must is personal obligation. It expresses our feelings =you feel
something is necessary or you strongly recommend it.
I haven’t spoken to Lucía for ages. I must phone her.
We haven’t got much time. We must hurry!
• Must is also typical in written rules, instructions, regulations…
Visitors must leave the museum befor 17.30
All passengers must show their boarding pass.
The asnwers to the exam must be written in blue.
• Don’t use must to talk about the past! Use have to
• Why did you have to leave so early?
• We had to leave early because the weather was awful.

11. OBLIGATION: MUST, HAVE TO
• Have to expresses that it is necessary to do something
because you are obliged to do it. It is impersonal, we don’t
use it for feelings, we use it for facts (external obligation)
You can’t turn right her. You have to turn left.
I have to wear glasses for reading.
Last week Jaime broke his arm and had to go to hospital.
Paloma has to travel a lot for her work.
• Logically, in questions use: do / does / did
Why do I have to do to get a new driving licence?
• **you can use «have got to» instead of «have to»
I’ve got to work tomorrow
When hasLiz got to go?

12. PROHIBITION: MUSTN’T, CAN’T
• MUSTN’T = it is necessary that you don’t do something = prohibition =
something is not allowed.
• Mustn’t is used when the prohibition is implied by the speaker.
I promised I would be on time. I mustn’t be late.
We must be quiet. We mustn’t make any noise!
You mustn’t take your mobile phone to school.
You mustn’t say things like that to your sister.
(teacher) you mustn’t be late for class!
• Can’t is also used for lack of permission, usually when something is
against the rules.
I’m sorry but you can’t park here.
You can’t take photos in the museum. They’re very strict!
Sorry- we can’t sell knives to under 18s!

13. LACK OF OBLIGATION
• When it is not necessary to do something (but you can if you
like) you can use:
You don’t have to tell him, but you can if you want to.
We have enough food at home, so we don’t need to go shopping.
I don’t have to be at the meeting, but I’ll go anyway.
Lucía doesn’t have to work on Saturdays.
We’ve got plenty of time. We needn’t hurry (=we don’t need to hurry)
** didn’t need to do ≠ needn’t have done.
I didn’t need to get up early, so I didn’t. (=I didn’t have to…)
This morning I got up early to take the train, but I was ready in 15 minutes,
so I needn’t have got up so early. (but I did)
Don’t / Doesn’t have to Didn’t have to
Don’t / Doesn’t need to Didn’t need to Needn’t

14. ADVICE: SHOULD, OUGHT TO
• SHOULD / OUGHT TO = it is a good thing to do or the right
thing to do = give advice or give and opinion.
You look tired. You should go to bed.
The government should do more to reduce vandalism.
• Use SHOULD to express that something is nor right or what you
expect.
I wonder where Tina is. She should be here by now. (this is not normal)
That man on the motorbike should be wearing a helmet.
• Use Should to express that you expect something to happen.
She’s been studying really hard, so she should pass the exam.

15. PERFECT MODALS: FORM
• In general, perfect modals help us express different meanings
about past actions.
I must have left my keys at home – they’re not in my bag.
My dad can’t have left for work because his car is still in the garage.
I didn’t know you wanted to see the play – I could have got you a ticket!
We had a really good holiday. It couldn’t have been better.
I can’t find my bag anywhere, I may have left it in the office.
I’m surprised Kate wasn’t at the meeting yesterday. She might not have
known about it.
I got up early yesterday but I needn’t have got up so early… it was Sunday!
I’m feeling sick. I shouldn’t have eaten so much cake at the party!
MODAL VERB + HAVE + PARTICIPLE

16. must have… / can’t have…
• They are used to express our deductions about past situations.
I didn’t hear the phone. I must have been asleep (=I’m sure I was asleep)
Sue hasn’t contacted me yet. She can’t have got my message (=I’m sure
she didn’t get my message)

17. could have… / couldn’t have…
• We use «could have + participle» to express a possibility
about the past.
The situation was bad, but it could have been worse.
• Something could have happened = it was possible but it did
not happen
Dave was lucky. He could have hurt himself when he fell, but he’s OK.
• We use «couldn’t have + participle» to say that something in
the past wouldn’t have been possible.
The trip was cancelled last week. Paul couldn’t have gone anyway
because he was ill (=it would not have been possible for him to go)

18. may have…. / might have…
• They express an assumption about the past = it is possible that
something happened / didn’t happen.
-I wonder why Nerea didn’t answer my phone call yesterday.
-She may have been asleep (=perhaps she was asleep)
• Could have… is similar to may / might have (only in the
affirmative)
You could have left your bag in the shop (= you may /might have left
it there).

19. needn’t have…
• It means: I did something but now I know it wasn’t necessary
I prepared everything for the dinner party but they didn’t come… I needn’t
have prepared anything! (but I did)
** needn’t have done ≠ didn’t need to do
I didn’t need to get up early, so I didn’t.
I didn’t need to get up early, but it was a lovely morning, so I did.
I got up early but it wasn’t necessary… I needn’t have got up so early
(but I did!)

20. should have… / shouldn’t have…
• They express the right/wrong thing to do in a past situation.
• «should have + participle» = you didn’t do it, but it would
have been the right thing to do.
You missed a great party last night. You should have come.
• «shouldn’t have + participle» = You did it, but it was the
wrong thing to do.
She shouldn’t have listened to our conversation. It was private.
**«Ought to have + participle» is also possible
• It was a great party last night. You ought to have come.