高三词汇精讲：第七章 情态动词

知识点归纳

Ⅰ.分类：

1.can, could, be able to

2.may, might

3.must, ought to, have to

4.will, would, used to

5.shall, should

6.dare, need

Ⅱ.情态动词的用法

1. c an, could和be able to的用法

(1)表示能力，如：He can speak English better than you.

(could和was able to都可表示过去的能力,但是could表示过去一段时间内稳定的能力，was able to表示一次性的能力)

(2)表示怀疑、猜测或一种客观的可能性，如：

Can this green bike be Liu Dong's?

(3)表示请求允许和许可时can可以和may换用，如：You can (may) go home now./ Can I watch TV?

(4)表示惊奇，怀疑，不相信，如：

This can’t be true!/ How can you so careless?

2.may和might的用法

（1）表示允许或征询对方许可

——May I use this dictionary?（Might更加委婉）

——Yes, please. 或 --- Certainly./ --- No, you mustn’t.

（2）表示现在或将来的可能性（注意不能用于疑问句）

They may (might) be in the library now.

比较：They may be in the library now .与They can’t be in the library now .

（3）表示祝愿

May you success!/ May you have a good time!

3. must, have to, ought to的用法

(1)must

①表示必须、应该之意，mustn't，表示不准或禁止之意，如：

We must study hard and make progress every day.

You mustn't touch the fire.

②以must提出的疑问句，如作否定回答时，要用needn't或用don't (doesn't) have to (不 必)来回答，而不用mustn't，因为mustn't表示的是“禁止”或“不许可”之意，如：

——Must we finish the work tomorrow?

——No, you needn't (don't have to), but you must finish it in three days.

③在肯定句中must表示推测，表示必定之意，如：

——Whose new bike can it be?

——It must be Liu Dong's. I know his father has just bought him a new one.

④表示“非得，偏要”做某事。

——How old are you, madam?

——If you must know, I am twice my son’s age.

(2)have to

have to和must的意义相近，但must侧重表示说话人的主观看法，而have　to则表示客观需要，如：

I must study English hard because I want to travel around the world. 

I had to give it up because of illness.

(3)ought to

①可以表示某种义务或必要，语气比should强

Everyone ought to obey the traffic regulations。

②表示推测，注意与must表示推测时的区别

He must be home by now .（断定他已到家）

He ought to be home by now .（不十分肯定）

This is where the oil must be.（比较直率）

This is where the oil ought to be. （比较含蓄）

4.dare, need的用法（主要用于否定句和疑问句）

will, would, used to的用法

(1)用于各人称，可以表示意志或决心

I have told him again and again to stop smoking, but he will not listen.

(2)在疑问句中用于第二人称，表示请求

Will you please tell me how to get to the park?

(3)表示一种习惯性的动作，表示总是或会要

Every morning he will have a walk along this river.

(4) would和used to表示过去的习惯时的区别：would比used to正式，并没有“现已无此习惯”的含义,而used to暗含“现在已不这么做”之意。

During the vacation he would visit me every week.

He told us he used to play foot ball when he was young

5.shall, should的用法

(1)shall

①用于第二、三人称，表示说活人的意愿，可表示“命令”、“警告”、“强制”、“威胁”或“允诺”等意，如：

He shall go first, whether he wants to or not.

②用于第一、三人称，表示说话人的征询对方意见或请求指示，如：Shall I open the door?

(2) should

①表示建议，劝告，命令: You should learn from each other.

②表示推测: They should be there by now, I think.

6. dare, need的用法

(1)两者作情态动词时，主要用于否定句和疑问句。谓语部分为need do sth./dare do sth. 如：

He needn't worry about us now.

He daren’t speak English before so many people, dare he?

(2)need提问的疑问句回答是注意助动词的选择

——Need I finish the work today?

——Yes, you must./ No, you needn’t.

(3)两者不作情态动词时，其谓语结构为need to do sth./need doing sth. /dare to do sth.

You need to practise reading aloud every day.

The dining room needs cleaning everyday.

7.情态动词+have done用法总结

 

情态动词	例句	用法
must have done	It must have rained last night, for the road was wet.	表示对过去发生的行为的推测，意为“肯定，准是”
can have done	He cannot have been to that town. Can he have got the book?	通常用于疑问或否定形式，表示对过去发生的行为怀疑或不肯定
could have done	I saw him just now. He couldn’t have gone to there. You could have done better,but you were too careless.	可表示“可能已经…”或过去没有实现的可能性“本来可以..”，有责备之意
may/might have done	It’s too late.I thing he may have gone to bed. He may not have finished the work.	表示对过去发生的行为的不肯定的推测
should/ought to have done	I should/ought to have helped her, but I never could. You shouldn’t /ought not to have treated your father like that.	用于肯定句时，表“本该做某事，而实际没做”；用于否定句时，表示“本不该做反而做了”。
needn’t have done	You needn’t have take a taxi, for it was very near. I didn’t need to clean the floor. My mom did it.	表示做了本不必做的事情。 注意：didn’t need to do表示“没必要做而实际上也没做”
had better have done	You had better have started earlier. You had better not have scolded her.	事后的建议，表责备，意为“当是最好做了某事”.否定句则为相反意思。
would rather have done	I'd rather not have said anything at the meeting.	表示“当时宁愿做了某事”，含后悔之意。

随堂练习

1. He was a good swimmer so he ______ swim to the river bank when the boat sank.

A. could        B. might        C. should        D. was able to

2. I went to the doctor's yesterday, I had to wait for half an hour before he _____ see me.

A. can          B. may        C. might               D. could

3. —______ this book be yours? 

—No, it _____ not be mine. It ______ be his.

A. Can, must, may  B. May, might, must  C. Can, may, must  D. Must, can, may

4. We didn't see him at the lecture yesterday. He ______ it.

A. mustn't attend                    B. can't have attended 

C. would have not attended            D. needed have attended

5. They ______ the plane, or perhaps they have been prevented from coming for some reason.

A. can have missed                 B. may have missed

C. can have lost                    D. may have lost

6. Since the ground is white, it ______ last night.

A. had snowed                    B. must have snowed

C. must be snowing                D. must have been snowing

7. —That must be a mistake. 

—No .it ______ be.

A. can't     B. isn't able to     C. can     D. was able to

8. How ______ so?

A. dare you to say         B. dare you say

C. do you dare say         D. dare to say

9. You are their teacher. You _______ care of them.

A. should to take         B. might to take 

C. ought to take          D. need to take

10. She is studying medical science now but she ______ a lawyer.

A. used to be      B. would be   C. were      D. had been

11. As a girl, she ______ get up at six every day.

A. would       B. will         C. might     D. should

12. —Shall I tell John about it?

—No, you ______. I've told him already.

A. needn't      B. wouldn't　　　C. mustn't    D. shouldn't

13—Would you like to go out for a walk?

—Yes, ______.

A. I'd like to    B. I'd like　　　C. I'll like to      D. I would

14. He ______ eating American food since he came here.

A. used to               B. has been used

C. has been used to        D. was used to

15. A computer ______ think for itself; it ______ be told what to do.

A. may not, must    B. mustn't, might C. shouldn't, could   D. can't, must

16. "May I go now?" "No, you ______. "

A. mustn't　　　B. needn't　　　C. mightn't　　　D. won't

17. You ______ pay more attention to your spelling next time.

A. would     B. should     C. will　　　D. shall

18. There ______ be a lot of small houses on both sides of the street.

A. used to    B. get used to    C. would      D. did use to

19. The girl _______ out alone at night.

A. dare not go   B. dare not to go    C. dares not go   D. does not dare go

20. He _____ you more help, but he was so busy.

A. might have given   B. might have     C. may have given   D. may give

真题冲刺

1. —I’m sorry. I ______ at you the other day. [2008江苏]

—Forget it. I was a bit out of control myself.

A. shouldn’t shout　　　　B. shouldn’t have shouted

C. mustn’t shout　　　　　D. mustn’t have shouted

2. Thank you for all your hard work last week. I don’t think we ______ it without you. [2008山东]

A. can manage　　　　　　　B. could have managed

C. could manage　　　　　　D. can have managed

3. Peter ______ be really difficult at times even though he’s a nice person in general. [2008辽宁]

A. shall　　　　B. should　　　　C. can　　　　D. must

4. Liza ____ well not want to go on the trip --- she hates traveling. [2008全国]

A. will       B. can             C. must           D. may

5. —What sort of house do you want to have?  Something big?

—Well, it ______ be big--that’s not important. [2008陕西]

A. mustn’t     B. needn’t      C. can’t        D. won’t

6. Although this ______ sound like a simple task, great care is needed. [2008四川]

A. must          B. may         C. shall        D. should

7. You ______ be hungry already. You had lunch only two hours ago! [2008浙江]

A. wouldn’t       B. can’t       C. mustn’t       D. needn’t

8. John promised his doctor he ______ not smoke, and he has smoked ever since. [2008北京]

A. might        B. should       C. could        D. would.

9. —I can’t find my purse anywhere.

—You _____ have lost it while shopping. [2008重庆]

A. may       B. can         C. should          D. would

10. According to the air traffic rules, you _____ switch off your mobile phone before boarding. [2008上海]

A. may　　　B. can　　　C. would　　　D. should

11. —What does the sign over there read?

—“No person ______ smoke or carry a lighted cigarette，cigar or pipe in this area．”[2007 四川]

A．will         B．may       C．shall        D. must

12. —What do you think we can do for our aged parents?

—You ______ do anything except to be with them and be yourself. [2007 重庆]

A. don’t have to　　　B. oughtn’t to    C. mustn’t　　　D. can’t

13. —My cat’s really fat.

—You _____ have given her so much food. [2007 浙江]

  A. wouldn’t      B. couldn’t        C. shouldn’t       D. mustn’t

14. As a result of the serious flood, two-thirds of the buildings in the area _____. [2007陕西]

A.need repairing　　B.needs to repair　　C.needs repairing　　D.need to repair

15. —She looks very happy. She _____ have passed the exam.

—I guess so. It’s not difficult after all. [2007 江苏]

A. should　　　B. could　　　C. must　　　D. might

16. We hope that as many people as possible _____ join us for the picnic tomorrow. [2006全国]

A. need　　　B. must　　　C. should　　　D. can

17. The weather turned out to be fine yesterday．I _____ the trouble to carry my umbrella with me．[2006江西]

A. should have taken　　　　B. could have taken

C. needn't have taken　　　　D. mustn't

18. Some aspects of a pilot’s job ______ be boring, and pilots often _____ work at inconvenient hours. [2006湖南]

A. can；have to    B. may；can     C. have to；may      D. ought to；must

19. ——Could I have a word with you, mum?

——Oh dear, if you ______.[2006浙江]

A. can           B. must        C. may            D. should

20.——I think I’ll give Bob a ring.

——You _____. You haven’t been in touch with him for ages. [2006江苏]

A. will          B. may        C. have to       D. should

答案

第七章 情态动词

随堂测试1-5DDCBB   6-10BABCA   11-15AAACD   16-20ABAAC

真题冲刺1-5BBCDC   6-10BBDAD   11-15CACAC   16-20DCABD