Content 1.Present and futurePresent and future 2.PastPast 3.ExercisesExercises
MODEL AUXILIARIES: PRESENT AND FUTURE 1.ABILITY: Can and Be able to -Can: ability Ex: I can swim. -Be able to is used in situations where can does not have the necessary grammatical form. Ex: I’d like to be able to swim.
2. CERTAINTY and UNCERTAINTY: -Must and can’t: make deductions, when we are more and less certain about something. Ex: You must be tired after your journey.(I suppose you are) That can’t be Sue. She’s in Brazil. (I’m sure it’s impossible) -May and might: express uncertainty or possibility. Might is less likely than may. Ex: It may not rain. I might go out. I don’t know. -Be bound to: refers to the future, whereas must refers to the present. Ex: You’re bound to see Paula if you go there. You must see Paula if you go there.
3.OBLIGATION: -Must and have to: +Have to: describes obligations made by someone else. Ex: you have to turn left here. (It’s the law) +Must: a personal obligation. Ex: You must start working harder! ( I say so) -Mustn’t and don’t have to: +Mustn’t: describes something which is not allowed. Ex: You mustn’t leaves any bags here. (It’s against the rules) +Don’t have to: something which is not necessary. Ex: You don’t have to apply yet. (It’s not necessary) -S-Should and ought to: have the same meaning; describe ‘what is good idea’ and can be used to give advice, or polite instructions. Ex: I think you should see a doctor. You ought not to continue.
- Should: describes actions we expected to happen. Ex: Brenda should be home by now. (She is expected to be) -Had better: refers present or future time and give advice how to stop something going wrong. Ex: I think you’d better leave now. (before it’s too late) You’d better not drive. (It’ might be dangerous) -Is/ Are to: used in formal instructions. Ex: No-one is to leave the room. You are not to leave the room.
MODAL AUXILIARIES: PAST 1. ABILITY - Could: describes past ability Ex: When I was young, I could run very fast. - Could and Was able to Was able to describes the ability to successfully complete an action Ex: Mary was able to help us. (She actually helped us) Mary could help us. (But perhaps she didn’t)
2. CERTAINTY and UNCERTAINTY -Must have and Can’t have: used to make deductions about past actions.The “have” form does not change. Ex: I must have left my wallet in the car. (I am sure I did). Jim can’t have noticed you.(I am sure he didn’t). - May have, Might have and Could have: express possibility or uncertainty about past actions.The “have” form does not change. Ex: Jean might have missed the train. (Perhaps she did) He may not have received the letter. (Perhaps he didn’t) You could have been killed!(It was a possibility) - Was/Were to be: describes something which was supposed to happen, but didn’t. It is formal in use. The “have” form does not change. Ex: He was to have left yesterday. (He was supposed to leave, but he didn’t)
3. OBLIGATION - Had to Had to is generally used as the past form of must Ex: Sorry I’m late, I had to take the children to school. The question form is Did you have to? Ex: Did you have to work late yesterday? - Should have or Ought to have These express the speaker’s feeling that a mistake was made. The “have” form does not change. Ex: You should have posted the letter yesterday. (You made a mistake) You shouldn’t have told me the answer. (You were wrong) - Needn’t have or Didn’t need to Needn’t have describes an action which happened, but was unnecessary. The “have” form does not change. Ex: I needn’t have bought more sugar. (I did, but we have enough) I didn’t need to buy more sugar. (I didn’t, because we had enough)