1. MODAL VERBS INTRODUCTION TO © 2011- 4º E.S.O by Beni Suárez Prado

2. General rules They help to express different meanings: ABILITY, OBLIGATION, OR POSSIBILITY They do not take -S for 3rd person ( except HAVE TO) They lack most tenses and forms They are followed by infinitive without TO (except HAVE TO and OUGHT TO)

3. MOST COMMON MODAL VERBS CAN COULD HAVE TO MUST MIGHT/ MAY SHOULD/ OUGHT TO

4. ABILITY  It is expressed with CAN (present) and COULD (past) - I can speak English and French. - When my father was young he could run 10 km in 15 minutes.  The negative is formed by adding NOT to the modal verb - He can’t run for long because he suffers from asthma. - There were lots of people at the concert, so we couldn’t move.  Questions are made by inverting the SUBJECT and VERB - How long can you resist under the water without breathing? - Could you read properly when you were five years old?  BE ABLE TO is used for the other tenses - I have been able to drive since I was seventeen. - She will be able to go on working when her computer is fixed.

5. OBLIGATION  IN AFFIRMATIVE it is expressed with MUST and HAVE TO - Students must be in the classroom before the teacher arrives - My friend has to wear uniform at her school.  IN NEGATIVE they have different meanings MUST expresses OBLIGATION/ PROHIBITION - We mustn’t enter while they are playing. HAVE TO expresses NO OBLIGATION (absence of obligation) - You don’t have to do exercise 3 if you don’t want to. (Difference)

6. Some practice: CAN, COULD, CAN’T, COULDN’T Exercise 1Exercise 2 MUST, HAVE TO, MUSTN’T, DON’T HAVE TO Exercise 3 ( must, have to) Exercise 1 (must)Exercise 2 (have to) Exercise 4 (mustn’t) Exercise 5 (mustn’t, don’t have to) Exercise 6 (must, have to, mustn’t, don’t have to)

7. POSSIBILITY and CERTAINTY MUST CAN’T COULD MAY MIGHT We are CERTAIN that something it’s true DOUBT Sophie must be at work, it’s ten o’clock and she works from 8 to 2 pm I haven’t got any homework, I could go to the beach this afternoon I must help my mum, afterwards, I may go to the beach I might go to the beach, but I’m not sure because I’m really busy today. Sophie can’t be at work, it’s half past three. We are CERTAIN that something it’s NOT true

8. ADVICE We can express advice with the modal verbs SHOULD and OUGHT TO You should study harder if you don’t want to be studying all summer We ought to hurry up, the film starts in ten minutes and we are still at home We can also show advice with the expression “HAD BETTER” You’d better stay at home; you’ve got a terrible cold and it’s raining cats and dogs outside

9. Some practice: CAN’T and MUST COULD, MAY, MIGHT

10. MODALS + PERFECT INFINITIVE ( HAVE + PAST PARTICIPLE) COULD MAY HAVE + past participle MIGHT MUST HAVE + past participle Speculations about the past “ He could/may/ might have gone home” COULD HAVE + past participle Past ability when the action wasn’t performed “ I could have lent you the money” Deduction about a past action “ He must have taken sleeping pills” COULDN’T HAVE + past participle Certainty that something didn’t happen “ She couldn’t have left her baby at home” NEEDN’T HAVE + past participle An unnecessary past action “ He needn’t have cooked dinner”

11. SHOULD HAVE + past participle Obligation which was not fulfilled and we are sorry it didn’t happen “ We should have told him it was wet” Assumption about a past action “The letter should have arrived by now” SHOULDN’T HAVE + past participle It shows disagreement or criticism with a past action “ We shouldn’t have spent all our money in that house”