情态动词的用法
一．情态动词的基本用法
情态动词表示说话人对某一动作或状态的态度，它虽有一定的意义，但不能单独作谓语，其后必须接动词原形才能构成谓语。
1．表示请求、征求对方意见时用may， shall（用于第一人称）; can， could， would(用于各种人称)，其中could， would语气更加委婉一些。如：
May I keep the book for another week﹖
Shall I open the door?
Could you tell me whom this bike belongs to﹖
Would you please let me have a look﹖
注意：对于may，can开头的问句，肯定回答时一般仍用may或can，否定回答时应根据项原说话人的语气来选用mustn’t或 can’t；而could，would开头的问句的回答时，则不可用could 和 would。
（1）---May we stay here for another two days?
---Yes, you may. |\ No,you can’t. (不，不可以) No, you mustn’t.（不，不允许）
（2）---Could I use your dictionary﹖
---＿＿＿＿＿＿＿＿．
A． Yes， you could B． No， you couldn’t
C．Of course， you could D．Certainly， help you to it（Key：D）
2．表示“允许”时常用may， can。如：
You may／can take whatever you like in this room．
这间屋子里的东西你想拿什么就可以拿什么。
3．表示“必须”常用must， have to. Must 更强调说话人的主观看法，而have to 表示的却是客观的需要。Have to 比must 有更多的时态形式。Must 开头的问句,否定回答用needn’t 或don’t have to .
I don’t like the bag. I must buy a new one.
The TV set is broken. I have to buy a new one.
You will have to walk home by yourself tomorrow.
-Must I finish the work before Saturday﹖
-Yes，you must． （ No，you needn’t ／ don’t have to．）
4．can表示有能力做某事，它只有一般现在时和一般过去时两种时态。一般情况下可与be able to互换，但be able to比can 可用于更多的时态。如：
I think the baby will be able to walk in another two months．
另外，当表示过去成功地做成了某事时一般用was ／ were able to，而不用could。 如：
Luckily， everyone was able to escape from the fire．
5.表示“应该”时用should 和ought to
We should respect the elder.
6.情态动词在一般时否定句中的用法
can't(can not) 表示“不能”， may not 表示“可能不, 也许不”， mustn't(must not) 表示“一定不要”，“不许可”，needn't (need not) 表示“不必”，
I can’t promise you anything but I will do what I can.我不能答应你什么，但我会尽我所能
That may or may not be true. 这可能是真的，也可能不是。
You may ask him but he may not answer you. 你可以问他，但他也许不会回答你。
You mustn't criticize her in that way. 你不许那样批评她。
You needn't come tomorrow. 你明天没必要来了。
二．情态动词表猜测的用法：must , may ,might, can, could 都可以表示推测。
Must 表示“想必，一定”用于肯定句中，may \ might 表示“或许，也许”可用于肯定句、否定句中。否定句和疑问句中用can \ could , 表示“（不）可能”“会（吗）？”。其中might t和could 不表示时态，只是语气比can 和may 弱些。下面心must为例：
1.表示对现在或将来情况的推测、判断用“must + do ”
I have just dropped in on him. He must stay at home.我刚刚拜访过他。他现在一定呆在家里。
The man must be your head teacher.那人一定是你们的班主任
2.表示对过去的情况或已经发生的事情进行推测、判断用“must + have +done”
The road is wet. It must have rained last night.路上是湿的。昨晚一定下雨了。
I didn't hear the phone. I must have been asleep. 我刚才没有听到电话，我想必是睡着了。
The boy must have finished his homework. 那男孩想必已经完成了他的家庭作业了。
3.表示对现在正在进行情况进行推测、判断用“must + be +doing ”
The girl is not out. She must be doing her homework now.那小女孩没有出门。她现在一定在做家庭作业。
At this moment, our teacher must be correcting our exam papers.
这时，我们老师想必在批改试卷
4．表示对过去某时正发生的事情进行推测、判断用“must +have +been +doing“
---Why didn't you answer my phone call? 你为什么没有接电话？
---Well, I must have been sleeping, so I didn't hear it. 我当时一定是在睡觉，所以没听到。
5．句子中含有表示猜测的情态动词时，其反意疑问句的构成不能再用原句中的情态动词，而应根据原句在去掉情态动词的情况下的主谓关系来确定其反问形式。如：
The man in the white clothes must be a doctor，______ he﹖
He must have an uncle abroad， _________ he﹖
She must have seen the film before， ________she﹖
You must have met Uncle Wang in the shop yesterday， _______you﹖
举一反三：
I don't know where she is. She _________in Wuhan.我不知道他在哪儿，也许在武汉。
She_______________ to see her doctor last week, but I am not sure.
上星期或许她去看医生了，但我不敢肯定。
Don’t worry， your husband ________________ seriously. 别急，你丈夫也许伤得不厉害。
There is no light in the room. She___________at home now.
房间里没有灯光。她现在不可能在家里。
He _____________ at the office last night, for he had gone to a party at six in the afternoon.昨晚他不可能在办公室工作，因为在晚上六点他得参加一次聚会。
Ling Ling ____________the piano now. She went to the bookshop with her mother a few minutes ago.玲玲不可能在弹钢琴。几分钟前她和她母亲去书店了
情态动词表示"推测、判断"的用法专练
1.-Are you coming to Jeff's party?
-I'm not sure. I________go to the concert instead.(NMET 2000)
A. must B. would C. should D. might
2.The river is rising. It ________last night.
A. must be raining B. must rain C. might have rained D. must have rained
3.-Why! I couldn't get you on the phone this morning.
-We ________tennis in the yard when you phoned.
A. must be playing B. could be playing C. must have played D. must have been playing
4.You must have seen the film last night, ________ you?
A. haven’t B. mustn't C. didn't D. hadn't
5.This________be a woman's bag. It must be a man's.
A. needn't B .can't C .may not D. mustn't
6.________it be John who did it?
A. Will B. Can C. Would D. May
7.It rained every day during their holiday, so they________a very nice time.
A. wouldn't have had B. couldn't C. can't have had D. shouldn't have 8.Peter________come with us tonight, but he isn't very sure yet.
A. must B. may C. can D. will
9.Jenny must have won the match,________?
A. hasn't she B. doesn't she C. mustn't she D. can't she
10.Mr. Zhuo must be working in the office, ________he?
A. mustn't B. can't C. doesn't D. isn't
参考答案1-5:DDDCB 6-10:BCBAD
三．情态动词在虚拟语气中的用法
“情态动词＋完成式” 用于虚拟语气中多表示责备的感情色彩，具体用法如下：
1．“should ／ ought to ＋完成式” 表示 “本应当做某事，而实际上并没有做”；“shouldn’t ／ oughtn’t to＋完成式”表示 “本来不应当做，而实际上却做了”。如：
You shouldn’t have gone to bed again when you woke up at five．
2．“may／might ＋ 完成式” 表示 “本来可以干某事却没有干”，突出其可能性；而 “could
＋ 完成式” 表示“本来能够做某事，但实际上却没有做”。如：
He might have given you some help， however busy he was．
3． “needn’t ＋完成式” 表示 “本来没必要做某事，实际上却做了”。如：
There was plenty of time． She needn’t have hurried．
1) It around nine o’clock when I drove back home because it was already dark.
［A］ must be ［B］ must have been ［C］ can’t be ［D］ should have been
2) John’s score on the test is the highest in the class;
A］ he should study last night ［B］ he should have studied last night
［C］ he must have studied last night ［D］ he must had to study last night
3) You yesterday if you were really serious about your work.
［A］ ought to come ［B］ ought to be coming
［C］ ought to have come ［D］ ought have come
4) “We didn’t see him at the lecture yesterday.”“He it.”
［A］ mustn’t attended ［B］ couldn't have attended
［C］ would have not attended ［D］ needn’t have attended
5) You ______all these parcels yourself. The shop would have delivered them if you had asked a shop assistant.
［A］ didn’t need to carry ［B］ needn’t have carried
［C］ needn’t carry ［D］ didn’t need carry
key:1-5:BCCBB
四．几个情态动词常考的句型：
1)．may/might (just) as well “不妨，最好”，与had better相近；
Since the flight was cancelled, you might as well go by train.
既然航班已经取消了，你不妨乘火车吧。相当于you had better go by train。
You may as well keep a certain distance from that mad man. 你们还是离那疯子远点为好。
You might as well go home now.你还是现在回家为好。
2) ．cannot / can’t…too …“越……越好，怎么也不过分”。注意这个句型的变体cannot…over….如：
You cannot be too careful when you drive a car.驾车时候，越小心越好。
The final chapter covers organizational change and development. This subject cannot be over emphasized .
3) ．usedn’t 或did’t use to 为used to (do) 的否定式。
4）．should 除了“应该”一层意思外，还有“竟然”的意思。如：I didn’t expect that he should have behaved like that. 我无法想象他竟然这样做。
5). 另外还须注意：shall可用于第二、三人称，表示许诺、决心、命令或警告。如：
You shall lose your job if you don’t do as I tell you．
如果你不按我说的做，你将失去工作。
五．情态动词被动关系的主动表达法
1． want, require, need “需要”， 接动名词表示被动意义。
Your hair wants cutting
The floor requires washing.
need既可以用need to be done 也可以使用need doing ，两种形式都表达被动的意义
The house needs painting= the house needs to be painted.
The watch needed repairing= the watch needed to be repaired.
练习：
1- ________ I speak to May, please?
-I'm sorry she ________ come to the phone because she isn't in.
A.Might; won't B.Can; mustn't C.May; can't D.Could; shouldn't
2.-I want to know if I ________ smoke here.
-No, you ________ . Could you see the sign "NO SMOKING" there?
A.can; needn't B.must; can't C.shall; won't D.may; mustn't
3．.My wife never remembers my telephone number. She always ________ look it up.
A.must B.should C.would D.has to
4．.-Must I go to work with you?
-No, you ________ . Linda ________ go with me.
A.mustn't; can B.can't; has to C.daren't; should D.needn't; may
5.- ________ I tell Mary the test results?
-No, you ________ . She's already got the score.
A.Will; won't B.Shall; needn't C.May; mustn't D.Can; don't
6.Joan ________ come with us this afternoon, but she isn't very sure yet.
A.can B.may C.must D.will
7．.The fire spread through the building very quickly but everyone ________ get out.
A.had to B.would C.could D.was able to
8.-Is John coming by train?
-He should, but he ________ . He likes driving his car.
A.can't B.needn't C.may not D.mustn't
9．.He doesn't have to work tomorrow, but you have got to, ________ you?
A.don't B.haven't C.haven't got D.can't
10.If I ___________ go with you, I should feel very glad.
A. can B. could C. should D. may
11.-When can I come for the photos? I need them tomorrow afternoon.
-They ___________ be ready by 12:00.(NMET'98)
A. can B. should C. might D. need
12.One ought ___________ for what one hasn't done.
A. not to be punished B. to not be punished C. to not punished D. not be punished
13.Johnny, you ___________ play with the knife, you ___________ hurt yourself.(NMET'96)
A. won't; can't B. mustn't; may C. shouldn't; must D. can't; shouldn't
14.I thought you ___________ like something to read, so I have brought you some books.
A. may B. might C .could D. must
15.If it ____ rain tomorrow, I wouldn’t ride motorbike there.
A. will B. would C. should D. shall
Key:1-5：CDDDB 6-10: BDCBB 11-15: BABBC
情态动词专练
Multiple choices:
1. If she had worked harder, she____
A: would succeed B: had succeeded C: should succeed D: would have succeeded
2 The plant is dead. I ____it more water.
A: will give B: would have given
C: must give D: should have given
3.Why didn't you tell me there was no meeting today? I ________ all the way here through
the heavy snow.
A. needn't have driven B. can't have driven
C. must have driven D. shouldn't have driven
4. We ____for her because she never came.
A: needn’t wait B: shouldn’t have waited
C: mustn’t wait D: mustn’t have waited
5. you____ return the book now. You can keep it till next week if you like.
A: can’t B: mustn’t C: needn’t D: may not
6. Where is my pen? I ____ it.
A: might lose B: would have lost C: should have lost D: must have lost
7. He ____ you more help, even though he was very busy.
A: might have given B: might give C: may have given D: both A and C
8..Janny _____ have kept her word. I wonder why she changed her mind.
A: must B: should C: need D: would
9. The room is in terrible mess; it _________ cleaned.
A) can't have been B) shouldn't have been
C) mustn't have been D) wouldn't have been
10.She was thankful that she'd had her baby in hospital; otherwise, she thought, the baby _____.
A) died B) had died C) might have died D) might die
11.You ______ all those calculations! We have a computer to do that sort of thing.
A) needn't have done B) shouldn't have done
C) must not have done D) cannot have done
12I'm not feeling well in the stomach, I _______ so much fried chicken just now.(2002,上海)
A. shouldn't eat B. mustn't have eaten C. mustn't eat D. shouldn't have eaten
13.-There were already five people in the car，but they managed to take me as well.
-It _______ a comfortable journey.(NMET 1995)
A. can't be B. mustn't have been C. shouldn't D. couldn't have been
14.-Why! I couldn't get you on the phone this morning.
-We ________ tennis in the yard when you phoned me.
A. could be playing B. must be playing
C. must have been playing D. should have played
15.-We didn't see him at the lecture.
-Neither did anybody else. He ________ it.
A. may not have attended B. mustn't attend
C. can't have attended D. couldn't attend
16.-Do you still remember when we went to the Great Wall?
-I can't remember it well, but ________ it have been sometime last May?
A. should B. must C. could D. would
17. ..-I wonder why Mr Lin didn't come to work.
-I am afraid he ________ ill.
A. could be B. should have been C. must be D. might have been
18.She ________ the hospital so soon, for she hasn't yet recovered.
A. wouldn't have left B. shouldn't have left
C. needn't leave D. hadn't left
20..Put on more clothes. You ___________ be feeling cold with only a shirt on.
A. can B. could C. would D. must
Judge the following sentences to see if they are right. If not, try to correct it.
1. Plastics is often used to making all kinds of containers.
2. All the passengers could leave the ship in the lifeboats before the ship sank.
3. He dares not climb the high wall without any help.
4. Where there is no air, there may be no life.
5. May he be waiting for us at the gate?
6. ---Might/ Could I borrow your typewriter please?
--- Of course, you might/ could.
7. --- Do you know where Jane was last night?
---She may have been in the night club.
8. They can’t leave. You see, their schoolbags are here.
9. Let’s hurry. They must wait for us.
10. He can have passed the test, but he wasn’t careful enough.
11. You didn’t need to telephone him. He has already known about it.
12. I slept until on Sunday, as I needn’t have gone to work.
13. A child need at least 9 or 10 hours’ sleep every day.
14. If you will keep to the rules here , you will do as you please.
15. The officer said to the solider: “You shall not leave your post before 10 o’clock.
情态动词在高考中
1. (北京卷)26. He __________ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside.
A. should B. must C. wouldn’t D. can’t
2. （山东卷）34. He paid for a seat, when he ______ have entered free.
A. could B. would C. must D. need
3. (广东卷)33. -- I've taken someone else's green sweater by mistake.
-- It ______ Harry's. He always wears green.
A. has to be B. will be C. mustn't be D. could be
4. （湖北卷）32．-Do you know where David is? I couldn’t find him anywhere.
-Well . He have gone far-his coat’s still here.
A．shouldn’t B．mustn’t C．can’t D．wouldn’t
5. （湖北卷）33．If I plan to do anything I wanted to ,I’d like to go to Tibet and travel through as much of it as possible.
A．would B．could C．had to D．ought to
6. （湖南卷）24. – Lucy doesn’t mind lending you her dictionary.
-- She ______ . I've already borrowed one.
A. can't B. mustn't C. needn't D. shouldn't
7. （湖南卷）31. The more I think about him, the more reasons I find for loving him ___ I did.
A. as much ms B. as long as C. as soon as D. as far as
8. (江西卷)22．-Tom is never late for work. Why is he absent today?
-Something ________ to him.
A．must happen B．should have happened
C．could have happened D．must have happened
9. （全国卷3）19．John, look at the time. ___________ you play the piano at such a late hour?
A．Must B．Can C．May D．Need
10. （全国卷1）26．Tom , you leave all your clothes on the floor like this !
A．wouldn’t B．mustn’t C．needn’t D．may not
11. （上海卷）27. There _________ be any difficulty about passing the road test since you have practiced a lot in the driving school.
A. mustn’t B. shan’t C. shouldn’t D. needn’t
12. （浙江卷）9. The World Wide Web is sometimes jokingly called the World Wide Wait because it _________be very slow.
A．should B．must C．will D．can
13. （重庆卷）33. I was on the highway when this oar west past followed by a police car. They ____ at least 150 kilometers an hour.
A. should have been doing B. must have been doing
C. could have done D. would have done
14. （天津卷）14. I _______have been more than six years old when the accident happened.
A. shouldn't B. couldn't C. mustn't D. needn't
15. （安徽卷）26. Helen ______ go on the trip with us, but she isn’t quite sure yet.
A. shall B. must C. may D. can
16. （辽宁卷）26．This cake is very sweet. You __________ a lot of sugar in it.
A．should put B．could have put C．might put D．must have put
17. (江苏卷)31. ---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.
---- Oh, dear! She _______ a lot of difficulties!
A. may go through B. might go through
C. ought to have gone through D. must have gone through
18.Johnny, you______ play with the knife, you______ hurt yourself.
A. won’t , can’t B. mustn’t, may C. shouldn’t ,must D. can’t, shouldn’t
19. Jack______ yet, otherwise he would have telephoned me.
A. mustn’t have arrived B. shouldn’t have arrived
C. can’t have arrived D need not have arrived
20.----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
21. ----Will you stay for lunch?
--- Sorry, ______ . My brother is coming to see me.
A. I mustn’t B. I can’t C. I needn’t D. I won’t
22.Sorry I’m late. I______ have turned off the alarm clock and gone back to sleep again.
A. might B. should C. can D. will
23．----Are you coming to Jeff’s party?
---- I’m not sure. I _____ go to the concert instead.
A. must B. would C. should D. might
24.My sister met him at the Grand Theatre yesterday afternoon, so he_____ your lecture.
A. couldn’t have attended B. needn’t have attended
C. mustn’t have attended D. shouldn’t have attended
25. I was really anxious about you. You _______home without a word.
A. mustn’t leave B. shouldn’t have left
C. couldn’t have left D. needn’t leave
26.---Is John coming by train?
--- He should , but he____ not. He likes driving his car.
A. must B. can C. need D. may
27.Naturally, after I told her what to do, my daughter ____ go and do the opposite!
A. may B. can C. must D. should
28. I often see lights in that empty house. Do you think I ____ report it to the police?
A. should B. may C. will D. can
29. ---I don’t mind telling you what I know.
---You______. I’m not asking you for it.
A. mustn’t B. may not C. can’t D. needn’t
30.---I’ll tell Mary about her new job tomorrow.
----You_____ her last week.
A. ought to tell B. would have told C. must tell D. should have told
31. “The interest ______ be divided into five parts, according to the agreement made by both sides, ” declared the judge.
A. may B. should C. must D. shall
32.----Isn’t that Ann’s husband over there?
----No, it_____ be him----I’m sure he doesn’t wear glasses.
A. can’t B. must not C. won’t D. may not
33.Tom, you _______ leave all your clothes on the floor like this!
A. wouldn’t B. mustn’t C. needn’t D. may not
34.John, look at the time._______ you play the piano at such a late hour?
A. Must B. Can C. May D. Need
35.There______ be any difficulty about passing the road test since you have practised a lot in the driving school.
A. mustn’t B. shan’t C. shouldn’t D. needn’t
36.----Lucy doesn’t mind lending you her dictionary.
----She_________. I’ve already borrowed one.
A. can’t B. mustn’t C. needn’t D. shouldn’t
37.The World Wide Web is sometimes jokingly called the World Wide Wait because it______ be very slow.
A. should B. must C. will D. can
38.He paid for a seat, when he_______ have entered free.
A. could B. would C. must D. need
39.---Catherine, I have cleaned the room for you.
---Thanks. You______ it, I could manage it myself.
A. needn’t do B. needn’t have done
C. mustn’t do D. shouldn’t have done
40. He _____ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside.
A. should B. must C. wouldn’t D. can’t
41.I_____have been more than six years old when the accident happened.
A. shouldn’t B. couldn’t C. mustn’t D. needn’t
key: 1-5:DDABC 6-10: DABAC 11-15: ADDCC 16-19: CDBD
BADCB CADBB CDBBC DD
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