情态动词的用法情态动词的用法

1 、 Could I borrow your book?

Yes. Of course you can.

2. Would you like to do it for me ?

Yes. I would.

一、情态动词注意事项

(1) 对现在或将来情况推测： must + 动词原形。

must 只能用于肯定。否定和疑问分别用 can’t和 can 。

He must tell a lie. Can he tell a lie ?

He can’t tell a lie.

*Must-should/ought to –may-might/could+do

可能性依次减弱

2 、推测语气

(2) 对过去情况推测： must (may, might)+完成时。

You must have met him before.

must—may—might 可能性依次减弱must 只能用于肯定句，译成“一定”。否

定和疑问分别用 can’t / couldn’t 和 can / could 。

Could /Can it have happened last night ?

It couldn’t/can’t have happened last night.

He must be reading, isn’t he?

You must do it yourself, don’t you?

He must have gone over the article, hasn’t he?

It must have rained last night, didn’t it?

3 、表猜测语气的反意疑问句的构成

would need used to do dare mustn’t don’t have to=needn’t

may/might do/have done不妨… ; 还是…为好

4 、 be able to must can have to

1 ）用于第一人称表将来。 I shall go to work after I have finished school.

2 ）用于一、三人称疑问句、表征求对方意见或向对方请求。Shall he come in? — Come in, please.

3 ）用于二、三人称，表示保证、承诺、威胁、警告。You shall be punished if you insist on doing it this way.

5 、 Shall

1 ）预测、可能。 They should be here by now.

2 ）说话人的感情。如惊奇、愤怒、失望等、“竟然”

You can’t imagine that well-behaved gentleman should be so rude to a lady.

6 、 should

1 ）对过去情况推测。 must/may/might have donecan’t/couldn’t/may not/might not have donecan/could have done…?

7 、情态动词 +have done

2 ）译成“本…” could/should/need have done.

You should have come here five minutes earlier.

3 ）虚拟语气（与过去事实相反的主句）

If you had followed my advice, you wouldn’t have been defeated.

情态动词典型例题专练

2. Johnny, you ______play with the knife, you ____hurt yourself. ( )

A. won't ; can't B. mustn't ; mayC. shouldn't ; must D. can't ; wouldn't

B

3. The fire spread through the hotel very quickly but everyone _____get out. ( D )

A.had to

B. would

C. could

D. was able to

4. ------When can I come for the photos ? I need them tomorrow afternoon.

-----They _____be ready by 12 : 00 . ( )

A. can B. should

C. might D. need

B

5. With so much work on hand, you ____to see the game last night. ( )

A.mustn’t go B shouldn’t goC. could have goneD. shouldn’t have gone

D

6.They are disappointed at the English party. They say that it ___better organized. ( D )

A.had been B. had to beC. must have been D. could have been

7.She must have forgotten about the class _______? ( )

A. doesn’t she B. mustn’t sheC. hasn’t she D. won’ t she

C

8. See who’s there ! _______ it be Mary ?

A. May B. MustC. Can D. will

C

9.Jenny ____with him at that time, for I was having dinner with her in my home. ( A )

A.can’t have been B. mustn’t have beenC. must be D. may be

10.Tom’s father promised, “You ___have a new computer if you pass the coming examination,” ( )

A.can

B. should

C. shall

D. may

C

11.---- Did you walked home by yourself last night ?

---- Yes, I did. But I think I _____. ( )

A. needn’t

B. shouldn’t

C. may not have

D. needn’t have

D

12.----Would you change this bucket for another ? It ______ hold water.

----- OK. I’m really sorry.

A.won’t B.can’t C.didn’tD.doesn’t

A

13. You ought to have helped him with his English, ____you ?

A. won’t you B. ought not youC. shouldn’t youD. wouldn’t you

C

14.--- I though I ____something burning. ( )

---Really ?A.smelled B. was smellingC. could smell D. might smell

C

15. She _____out alone at night. ( )

A. dare not to go B. dares not goC. doesn’t dare to go D. doesn’t dares go

C