情态动词的用法

一.情态动词总的用法

1）情态动词不能独立做谓语，要与动词原形（do）一起构成谓语；

我会英语 I can English. × I can speak English. √

2）情态动词没有人称和输的变化，即没有“三单” I can speak English. √ He can speak English. √ 二.情态动词一般用法

1. could和might用在疑问句中更多时候表示的是语气，与时态无关，注意答语。

Could I use your computer？ Yes, you can. No, you can’t Would you please turn up the radio? Yes, I will. No, I won’t.

2. must和may的一般疑问句的否定回答要分别用needn't和mustn't/can’t。

--May I use your book？

--Yes, you may/can. No，you mustn't/can’t. --Must I finish my homework today?

--Yes, you must /have to. No, you needn’t./don’t have to. 3. 几种与情态动词易混词的区别 1）need 的用法：

①情态动词：a: 多用于否定句和疑问句.

You needn’t worry=You don’t need to worry.

b: need一般疑问句,肯定回答用must或have to;否定用needn’t.

—Need I answer the question?

—Yes, you must/have to. No, you needn't.

②作行为动词

need 作为行为动词有人称和数的变化,后面可接名词、代词、动名词及不定式；可用于肯定句、疑问句和否定句中

1. She needs help.

2. I don't need to see the doctor. 3. Do you need to go at once? 4. I need a bottle of beer.(否定句) 2) can与be able to的区别

can只有一般现在时和一般过去时（could），而be able to有多种时态

We will be able to come back next week. Will you be able to drive?

3) must与have/has/had to的区别

①must表示主观所以译为“必须”；have/has to表示客观所以译为“不得不”。

It’s raining outside, so I have to wear raincoat. ②must形式单一；have /has to形式多样。

We will /shall have to ask Zhang Hong. Do I have to finish the task today?

4) may be与maybe的区别

Maybe it is rainy today.=It may be rainy today.

Maybe he gets up at 5:00 every day=He may get up at 5:00.

三.情态动词表猜测

1. 表猜测 must “一定，肯定” might（could, may） “可能，也许” can't “不可能，不会”

The dictionary must be mine. It has my name on it.

The CD might（could）belong to Tony because he likes listening to pop

music.

The hair band can't be Bob's because he is a boy.

2. must 和may 表猜测时的反问

It must be Carla's，isn't it？

It must belong to Carla，doesn't it？

1. We should do what we can ______(protect) the wild animals.

My teacher did what he could _______________ (make) his class lively. （13烟台）

He always do what he can _____(help) others.

2. The little boy spent as much time as he could ______(recite) the text yesterday. 3. The bridge can _____(build) this year.

判断正误 1. I can English. 2. He can speak English. 肯定否定回答

1. --Could I use your computer？ --Yes, you ___. No, you ____ --Would you please turn up the radio? --Yes, I ____. No, I ____. 2. --May I use your book？ --No，you ____.

--Must I finish my homework today? --Yes, you ____. No, you ____./____. 用表猜测的情态动词填空

1. The dictionary ____ be mine. It has my name on it.

2. The CD ____belong to Tony because he likes listening to pop music. 3. The hair band ____ be Bob's because he is a boy. 选择：

1. According to the new survey, everyone _____ to have at least eight ____ sleep at night.

A. need; hours B. need; hours’ C. needs; hours’ D. needs; hours 2. You ____ the coat. It’s warm outside.

A. needn’t to put on B. don’t need put on C. not need to put on D. needn’t put on

4. --- What should we for first if we want to develop our village? --- A lot of new roads _____, I think.

A. must build B. have to build C. must be built D. have built 5.---__________ I use your dictionary?

--- Of course. But please return it to me before you leave.

A. Must B. Need C. May

6.--- Is that man Mr. Smith?

--- It ______ be him. He has gone to New York on business.

A. may not B. needn’t C. can’t D. mustn’t 7.--- Thank you for helping me with my physics. --- ______. I hope you can do better in it.

A. Good idea B. See you C. I’m not sure D. You’re welcome 8. —Mr. Wang, must I come again to clean the classroom on Sunday? —No, you____ . I have asked Kate to do it.

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

9. — ______you come to my party on Sunday?

— Sorry, I’m not available. I ______study for the math test.

A. Can; must B. Must; can C. Need; may

D. May; can

10. ---Who will give us the speech on public manners? ---Mr. Brown_____,but I'm not sure.

A.can B. need C. must D. might 13. —Must I clean the classroom now?

—No, you_______. A. mustn’t

B. can’t

C. needn’t

14. Nowadays all passengers ______ go through safety check before take a train. A. can B. may C. must D. will

15. — Dick, ________ I use your e-dictionary?

— Yes, sure. ________ you give it to David after you use it? Should

16. — How often do I need to feed the dog?

— It ________ food every day, or it will be hungry.

A. must give

B. must be give C. must gave D. must be given

A. will; Would B. may; Might C. can; Could

D.

shall;

17. --Do you have any plans for this summer vacation? --I'm not sure. I ___ take a trip to Taiwan.

A. must

B. need

C. may

D. should

18．The woman ______ be our English teacher. She has gone to Canada.

A．can’t B．needn’t

C．mustn’t

19. It’s surprising that Mr. Ma’s little daughter _____ speak English so well.

A. must

B. can

C. mustn’t

D. can’t

21. —___________ I complete the composition today, sir?（15烟台） —No, you needn’t. You may ___________tomorrow morning.

A. Can, hand it in B. May, hand in it C. Must, hand it in D. Need, hand in it

22. –Whose book is this?（13烟台）

--It ________ our geography teacher’s. You see, his name is on it. A. can’t be B. can be C. mustn’t be D. must be 23. .—I think the man over there must be Bob.（11烟台） --- It_______ be him. He has______ to Australia.

A. can’t, gone B. can’t, been C. may not, been D. mustn’t, gone 24. –Who ____ it be walking in the garden? （10烟台） -- It ______ be Mr. Li. He has gone to the supermarket.

A. may, mustn’t B. might, may not C. can, can’t D. could, mustn’t 25．—Must I get up early tomorrow?(08烟台) —No, ________.

A. you mustn’t B. I don’t think you have to

C. you can’t D. you need 26.— Where is Mr. Smith? Have you seen him? — He _______ be in his office. （07烟台）

— He _______ be in his office, for I left there just now.

A. may, can’t B. can, may not C. man, mustn’t D. can, don’t have to 27.---________I come back before 11 : 00?（05烟台）

—No, you________. But you_________ be back later than lunch-time. A. Must, needn't, can't B. Can, can't, may C. Need, mustn't, must D. May, needn't, can't