MODAL VERBS

General Characteristics:1- They have no infinitives, past participles or -ing forms, and other

expressions are used instead. For example we use “be able to” instead of can and “have to”

instead of must.

Compare these examples: - Mary can speak English very well. - You will be able to drive a car when you are 18. (infin.) - I have never been able to understand my son. (past part.) - I love being able to get up late on Sundays. (-ing forms) - We must study hard for our exams. - You will have to study harder when you go to university. (inf.) - We have had to call the doctor because she doesn’t feel well. (past

part.) - Having to get up early every day is quite stressful. (- ing form)

2- Modal verbs have no -s on the third person singular. - She can play the piano. - He may come tomorrow.

3- Questions and negatives are made without “do” - Can your mother drive? - Should I dress up to go to the party? - You shouldn’t speak like that - You cannot smoke at school

4- They are followed by the infinitive without to of other verbs (except “ought to”)

- She could be in Paris or London or Tokyo - nobody knows

but - You ought to stop worrying about your weight.

EXPRESSING ABILITY: CAN, COULD, BE ABLE TO

CAN expresses ability to do something. (saber)

She can skate very well but she can’t swim (= She knows how to skate but she doesn’t know how to swim)

Notice this:*You will be able to speak English fluently

when you go to England.*Being able to speak several languages is

amazing.

COULD.A) General ability in the past. (sabía) - My grandfather could speak five languages. - When Tom was 16, he could run 100 metres in 11

seconds.

But if we refer to a particular situation, we have to use was/were able to (pudo...)

- The fire spread through the building very quickly but everyone was able to escape.

- They didn’t want to come with us at first but in the end we were able to persuade them.

Compare could - be able to: - Jack was an excellent player. He could beat anybody but

once he had a difficult game against Alf. Alf played very well but in the end Jack was able to him.

Couldn’t is possible in all situations (general or particular):

- We tried hard but we couldn’t persuade them to come with us.

- My grandfather couldn’t swim.

Could is used with verbs like “see, hear, smell”

- Although they were whispering, I could hear what they said.

POSSIBILITY AND DEDUCTIONCAN: General possibility. (poder) - It can be cold in Granada in winter. - Anybody can make a mistake. - You can swim because there is an indoor swimming-pool

in our town. MAY: Present of future possibility. - I may go to aerobics class. (puede que) - He may start a diet tomorrow.MIGHT/ COULD: Remote possibility in the present or

future. (pudiera ser que) - She might win the race, but she hasn’t trained hard

enough. - Are you sure about it?, You could be wrong. - Look at the sky. It could rain this afternoon.

POSSIBILITY IN THE PAST:May/ might/could have+ past part.

A guess about a past action. We do not know what actually happened.

Paul is late for work. He may have missed the bus, he might have overslept or he could have had an accident.

When you had the ability or possibility of doing something in the past; but you didn’t do it.

I could have gone to the party but I didn’t want to

LOGICAL DEDUCTION: MUST / CAN’T

The lights are on. She must be at home. (affirmative)

The lights are off. She can’t be at home (negative)

In the past…Paul didn’t answer my calls. He must have

been out all day.John can’t have studied hard. He failed the

exam

OBLIGATION/ADVICE/NECESSITYMUST/ HAVE TO Must expresses “moral obligation” (strong obligation) - I must write to Ann, I haven’t written to her for ages. (The speaker thinks it’s

necessary. It’s his/her moral obligation)Compare it with “have to”: - I have to wear a uniform in my school (it means external obligation)

In the second person: Must expresses speaker’s authority: - Doctor: You must cut down on your smoking. - Mother: You must wear a dress tonight. You can’t go to the opera in those

dreadful jeans.If you are talking to a friend you usually use “have to”: - It’s already 12 o’clock. Be careful, you have to be back home early.Have a look at some more examples: - The government really must do something about unemployment. (The speaker

personally feels that the government must do something)With “have to” the speaker is not giving his own feelings. He is just giving facts. - Ann’s eyes are not very good. She has to wear glasses.* For the past, future, past participle and inf, we have to use “have to” - There were no buses so she had to walk

ADVICE: We use SHOULD to give advice - You should eat more fresh fruit. - You shouldn’t waste so much time watching TV - Should we talk to him?OUGHT TO is quite similar to should, but less frequently

used. - You ought to come more frequently.HAD BETTER: in a specific situation. You suggest there

will be a problem if something is not done.I have a terrible headache.- You’d better go home.-You’d better not cry, you’d better not pout. Santa Claus is

coming to town.

Notice the difference:-It rained all the time and I didn’t take my umbrella. I

should have taken my umbrella.(it was the right thing to do but you didn’t do it)-It didn’t rain at all, but I took my umbrella.I needn’t have taken my umbrella.(you did something which wasn’t necessary)- I spent my holidays in sunny Spain so I didn’t

need to take my umbrella.(=didn’t have to)(it wasn’t necessary/ absence of obligation)- I spent my holiday in rainy England so I had to

take my umbrella. (obligation in the past)