Tieng anh

Presenter
Đỗ Thị Diệu
Nguyễn Thị Tường Vi
Modal auxiliaries
Content
Present and future
Past
Exercises
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)
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)
EXERCISE
Exercise 1
Exercise 2
Exercise 3
Exercise 4