Modal verbs are helping verbs that express moods like ability, possibility, necessity or other conditions. They are always used with a main verb and cannot stand alone. There are 12 modal verbs in English, some of which are considered "semi-modals" because they can be conjugated. Modal verbs also have perfect forms where they are used with "have" and the main verb's past participle form. Examples are provided to illustrate how modal verbs are used to express abilities, requests, possibilities, prohibitions and other meanings.

1. Modal Verbs UNIT 3

2. A Modal Verb , also called Auxiliary ; is a type of “helping” verb. They express the mood of a verb, such as; ability, possibility, necessity or another condition. They are used with a main verb to form a sentence or a question. So, they cannot be used without a main verb.

3. So, the structure will always be: SUB + MODAL + MAIN VERB(inf) + COMP She + can't + go + to your party

4. English has 12 modals, Some of them are called Semi-modals (these can be conjugated) Some of them have their Perfect Form = Modal + Have + Verb (Participle) Let's see them!

5. * Semi-modals in green. Can Could Be able to Can't May / Might May Could Would Must Have to = Need to Ability (Present and Past) Inability Disbelief Prohibition Possibility Formal Request Offer Obligation Necessity Must Have to Mustn't Needn't = Don't have to Should Ought to Shall...? Strong belief Prohibition Lack of necessity Advice Offer

6. Ability : Mary can swim fast. / I was able to finish my homework on time. Request : Can you call me tonight? Possibility : I can meet you later. / It may rain tomorrow. Inability : I can't eat a whole cake by myself. Prohibition : You can't drive without a licence. / You mustn't exceed the speed limit. Disbelief : That can't be the price – it's too cheap! Polite request : Would you open the window,please? Offer, suggestion : Would you like something to drink? / Shall I help you with your luggage? Strong necessity : You must bring your books to class. Certainty that sth is true : She's got a great job, she must be very happy. Obligation,necessity : I have to buy the tickets today. / I need to cook dinner tonight. Lack of obligation/necessity : You needn't / don't have to bring anything to the party. Advice, opinion : You should / ought to improve your level of english. EXAMPLES

7. Modals: Perfect form MUST HAVE MAY / MIGHT HAVE COULD HAVE COULDN'T HAVE Certainty that something was true. A guess about a past action. Ability to do something in the past which in the end wasn't done Certainty that something didn't happen WOULD HAVE SHOULD / OUGHT TO HAVE SHOULDN'T HAVE NEEDN'T HAVE Desire to do something in the past which in fact couldn't be done. Criticism or regret after an event. Criticism or regret after an event. An unnecessary past action.

8. EXAMPLES Certainty that something was true. A guess about a past action. Ability to do something in the past which in the end wasn't done Certainty that something didn't happen Rob has arrived late. He must have been in a traffic jam. She might have taken the wrong bus. You could have asked the doctor before taking that medicine. He couldn't have gone to the concert because he was doing a test. Desire to do something in the past which in fact couldn't be done. Criticism or regret after an event. Criticism or regret after an event. An unnecessary past action. I would have gone to the party, but I was too busy. You should have told me earlier. He shouldn't have forgotten about her birthday. You needn't have brought anything to my party.

9. Should / 'd better You should go to the doctor = You'd better go to the doctor. We'd better not buy that car. It's very expensive. You'd better tidy your room now! You'd better not take my car! SHOULD HAD BETTER Advice Advice much more like a Warning.

10. Now do the exercises on page 36 (SB) Ex 2. Tina no parece feliz. Ella no ha podido haber oído las nuevas noticias. Me siento bastante mal. No debería haber comido tanto. Consúltaselo a Pete antes de comprarle ese libro. Puede que lo haya leído. Te lo habría contado, pero me hicieron prometer que no dijera nada. No necesitamos haber venido tan pronto. El médico no está aquí aún. Ben no puede abrir la puerta. Ha debido perder sus llaves de nuevo. Es muy tarde para que vaya. Tendrías que haberme llamado antes.