1、第十一讲:情态动词一、常见考点: 1. can, must, may, should, might表示推测时的区别 2. cant,mustnt, may not, neednt等否定形式的用法 3. should和ought to表示“义务”和“推断”的用法 4. shall和will 作为情态动词用时的用法特点 5. need 和 dare 作为情态动词和实义动词用时的用法特点 6. had better, used to 和would rather的各类用法特点。二、 情态动词的基本用法:1. can(could)(1) 能.、会.(表示能力) He can speak English
2、better than you注意:be able to 强调经过努力、克服困难等完成某事;则was/were able to表示过去经过努力等成功的做成了某事;could 表示原来具备某种能力,现在没有这种能力了(2) 能够。、可以。(表示可能、许可) “May I use your telephone?” “Yes, you can.” / You cant park your car in this street. 注意:此时,can可以表示表示理论上的或逻辑上的,或偶尔发生的事情,或一时的事情或特有的事情。如:It can be windy on the top of the moun
3、tain./ she can be forgettable sometimes./ Tigers can be dangerous. /Jogging can be harmful for the health. The temperature can fall to -60.(气温可降至零下60) (3) 请做。、得。(表示温和的命令) I will do the cooking, and you can do the washing. 我来做饭,请你去洗衣服(4)能不能。,要不要。(用于疑问句,表示客气的请求、提议) Can you give me a lift to the statio
4、n? Cant you lend me 10 dollars?请你借给我10美元吧?(5)构成下列特殊句式: can not/ can never.too.或cannot.enough.“无论怎么。也不过份; 越。越好 ;非常。” One cannot be too carefull. 越认真越好。 cannot help doing./ cannot help but do./ cannot but do.”“禁不住;不由得;不得不” When a close friend dies, you cannot feel but sad. 当一个密友死的时候 , 你会禁不住伤心的. (6) ca
5、n 还可以用于一般疑问句和否定句表示推测?someone is knocking. Who can it be ? 而在肯定句中表推测要用must和may2. may/ might(1) 可以。(表准许、请求) eg: You may go home now, Susan. 苏珊,你现在可以回家了(2) 但愿;祝。(表愿望、祝福;此时,句子要用倒装语序) May you succeed.祝你成功。(3) 为了,为了能够(用于目的状语从句so.that./ such.that.)He works hard so that he may get good grade.(4) 即使,无论(用于让步状
6、语从句中) Whatever he may say, I dont believe him.(5) 构成句型 may as well do sth/ might as well do sth (不妨去做某事,还是做某事的好)(6) May 的否定回答不用may,-May I use your bike?-No, you mustnt/ Youd better not. / please dont (肯定:Yes, please. / Certainly)3. must (1) 必须、得、要(表义务、必要性、命令)Animals must eat to live.(为了活下去,动物必须吃东西。)
7、 -Must I washing the sidhes at once? -No, you neednt. / yes , you must 注: mustnt 表示“禁止、不准”。Eg: You mustnt play with the knife; you might hurt yourself. (2) 必定(表必然性)。 Everyone must die. 每个人都必定会死。(3)偏偏、偏要、硬要(表固执、不满等):If you must know, Im going to help him look for an apartment.如果你偏要知道,那我告诉你,我要去帮他找一套公寓
8、。(4)想必、一定、准是(表推测,只用于肯定句)。 He must be ill. He looks so pale. (5) must 的否定回答用: No, you neednt/ No, you dont have to4. shall (1) 用于第一、第三人称,表示征求对方意见,请求指示等:Shall we go out for a walk?注:may 征求对方的许可,而shall是征求对方意见May I have a look?我能看一下嘛?Shall I have a look? 要我看一下嘛?(2) 用与第二、第三人称,表示说话人的命令、警告、强制、允诺、威胁或决心等:eg:
9、He shall be sorry one day, I tell you. 我告诉你,他早晚有一天会后悔的(警告) Dont worry. You shall get the answer this very afternoon. (允诺)。 Nothing shall stop us from carrying out the plan. (决心)(3) 应。/须。/ 得。(用于法律、规则等条文中): The fine shall be given in cash.罚款应以现金5. should (1) 应该(表义务、责任) :We should attend the meeting .我
10、们应该参见这次会议。(2)应该会、想必会、一定会(表预期):The concert should be great fun. 音乐会一定很有意思。(3)竟然、居然(表惊讶、遗憾):Im glad that your story should have won the first prize. 我很高兴,你的小说居然赢得头奖。(4) 一旦、万一(用于条件状语从句中):If she should know the truth, she would be greatly depressed.万一她知道了实情,她将会非常失望(5) 用于一些表示命令、建议、请求等动词后面的that从句中,如:sugge
11、st, demand, recommend,advise,且,should可以在这个that从句中省略。They demanded that she (should) leave at once.(6) 究竟是、到底是(与疑问词连用,表示意外、纳闷、惊讶等)Who should come in but my old friend Betty!我当是谁进来了呢,原来是我的老朋友贝蒂啊。(7) 用于与将来事实相反的if条件状语从句中,此时省略if , 还可以引起倒装If I shoud be free tomorrow, I would go wth you .=Should I be free
12、tomorrow, I would go with you.6. will(1) 表意愿,用于各种人称陈述句:If you will read the book, Ill lend it to you. 如果你愿意读这本书。(2)表请求,用于疑问句:Will you close the door? It is a bit cold. (3) 表示某种倾向或习惯性动作:The door wont open.(这门打不开) Fish will die out of water.(4) 表命令、叮嘱: No one will leave the examination room before 12
13、oclock.12点前谁也不得离开考场。(5)表猜测:That will be the postman at the door. 门口想必是邮差。7. would (1) 常常、经常(表过去的习惯性动作):We would stay up all night talking our future.区别:used to _(2) 老是、偏要(表示说话者的厌烦、焦躁):Thats exactly like Susie. She would come to me just when I was busy.苏西就是那个样子,她老是在我忙碌的时候来找我。(3)就是(不能)(用于否定句,主语一般是物,表某
14、物一时的、暂时的特性)That door wouldnt open.(4) 表示客气的请求、建议;或婉转的表达个人的想法、看法:Would you mind if I open the window?8. ought to (1)表义务、应该,口气比should稍重。 You are his father. You ought to take care of him. (2) 表推测,暗含很大的可能: Han Mei ought to konw his telephone number.9.used to 表示过去的习惯性动作或状态,现在不发生或存在。疑问式和否定式有两种:如I usednt
15、to smoke.= I didnt use to smoke.10. have to (would rather+do) have to和must的意义相近,只是 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 hard. I had to give it up because of illness.11. need 和 dare 这两个词都即可用作情态动词, 也可用作实义动词。 用作情态动词,主要用于否定句和疑问句; 用作实义动词,主要用于肯定句(当然也可以用于否定句等) 用作实义动词:You neednt do it yourself.=
16、You dont need to do it yourself.I need to tell them the news. need的主语是物时,其后的动词可以是:doing或to be done. The table needs painting. = The table needs to be painted. dare 在否定句中,用作实义动词时,其后的to可带,也可以不带。 He did not dare (to) look up. 他不敢抬头看。 I dare say. 为固定习语,意思是“我敢说。”三、 情态动词+have done的用法:情态动词+have done一定表述的是过
17、去的事情,且表示对过去发生的事情的推测、判断,或表某种强烈的语气(如惊讶、责备、赞叹等) must + have done 表“过去肯定发生了某事”。The room is clean. Someone must have cleaned it. 注:绝对没有下面的形式:mustnt have done. may/might + have done 表示“过去可能发生了某事”,其中might 的语气要婉转些;但是主句中动词是过去时,一定要用might,如He said she might have missed the train. could + have done,表示“过去本来能够做成某
18、事,但是没有做到”:You could have succeeded. cant/couldnt have done 表示“绝不可能发生了某事”:He couldnt have taken all the medicine at a time. should/ought to +have done, 表示“过去本来应该做某事,但实际上未做” You are late again. You ought to have come one hour earlier. shouldnt+ have done/ 或oughtnt to have done, 表示“过去不应该做某事而做了某事”This i
19、s my letter. You shouldnt have opened it. neednt + have done 表示“本没有必要做某事,而做了” There was plenty of time, so she neednt have hurried. 有充足的时间,所以她没有必要哪么急的。注:如果是对现在或将来的情况进行推测或判断,要用:“情态动词 + V-原”。四、must 表示推测时:其反义疑问句的构成如下:He must be a teacher, _?She must have finished the work, _?She must have finished the
20、work last night, _?She must have finished the work by the end of last month, _?五:同步巩固训练:基础训练:1. -shall I tell John about it? -No,you _.A. neednt B.wouldnt C.mustnt D.shouldnt2. Peter _come with us tonight. But he isnt very sure yet.A. must B.can C.may D.will3. I didnt see her in the meeting room thi
21、s morning. She _ at the meeting.A. mustnt have spoken B.Shouldnt have spokenC.neednt have spoken D.cant have spoken4. I didnt hear the telephone.I _ asleep.A.must be B.must have been C.should be D.should have been5. -_ I open the door for you?-No,thanks.I can manage by myself.A. Will B. May C. Shall
22、 D. Should6. One ought _ for what one hasnt done.A.not to be punished B.to not be punishedC.be not to punished D.not be punished7. The fire spread through the hotel very quickly but everyone _escape. A.had to B.would C.could D.was able to 8. I told Sally how to get here,but perhaps I _ for her.A.had
23、 to write it out B.must have written it outC.should have written it out D.ought to write it out 9. A computer _ think for iself; it must be told what to do.A.cant B.couldnt C.may not S.might not 10. Tell Tom that he _have the book next week. A.shall B.will C.can D.would11. If you really want yoursel
24、f to be in good health.you must_always_so much. A.not;be smoking B.not;have smoked C.to not;be smoking D.not be;smoked12. With so much work on hand,you _to see the game last night. A.mustnt go B.shouldnt go C.couldnt have gone D.shouldnt have gone13. Someone is knocking at the door.Who _it be?A.may
25、B.must C.will D.can14. -Look,it _be Tom. -No,it _be him.He has gone to Beijing. A.may,mustnt B.must,may C.must,cant D.can,may not15. Dont be worried.The news _ be ture.A.may not B.mustnt C.neednt D.wont16. Its possible that Mr.wu is working now. The sentence means _. A. Mr .Wu must be working now B.
26、 Mr . Wu cant be working now C. Mr . Wu should work now D. Mr .Wu may be working now 17. You mother must be at home,_ she? A.mustnt B.doesnt C.isnt D.cant18. - _ I watch TV this evening?- Yes,but you _ finish your homework first.A. Must;can B. May;must C. Must;may not D. Must,cant 19. -_I sleep here
27、?-No,you _.A. May;neednt B. May;mustnt C. Can;need D. May;may20. -Must I turn off the light now?-No.you _.A. neednt B.mustnt C.cant D.wont21. You _ so early.A.need come B.doesnt need come C.needs come D.neednt come22. We _ them.They can do it by themselves.A.need help B.dont need help C.dont need to
28、 help D.neednt to help23. Youd better _ in class.A.not talk B.not to talk C.dont talk D.not talking24. You _ go with us now,or you will be late. A.shall B.should C.would D.could25. - Need I go to work now? -Yes,you _. A.need B.can C.may D.must 26. Could you tell me if there _plenty of rain in your h
29、ometown?A.is B.would be C.are D.was 27. A boy was crossing the street in front of my car,and I _ stop very quickly.A.must B.have to C.has to D.had to 28. Xiao wang _have been to Japan.He has never told this.A.will not B.can not C.shall not D.may not 29. She _have had a hard life since she looked muc
30、h older than her age.A.may B.may not C.mustnt D.must 30. He went home because his mother was ill.We _have waited for him at the bus station for a long time.A.neednt B.need C.must D.shall31. You are late for class.You _have come to school earlier.A.shall B.must C.will D.should 32. Mr Wang is wet thro
31、ugh.He _caught in the rain. A.must be B.must have been C.must has been D.must nave(答案详解见最后面)2007年真题:1. Hows your tour around the North Lake? Is it beautiful? It _ be, but it is now heavily polluted. 2007 全国卷I A. will B. would C. should D. must 2. Guess what! I have got A for my term paper. 2007 上海卷
32、Great! You _ read widely and put a lot of work into it. A. mustB. shouldC. must have D. should have3. The teacher _have thought Johnson was worth it or she wouldnt have wasted time on him, I suppose. 2007 安徽卷 A. should B. can C. would D. must4. In crowded places like airports and railway stations,yo
33、u_ take care of your luggage. 2007 北京卷A. can B. may C. must D. will5. My MP4 player isnt in my bag. Where I have put it? 2007 福建卷A.can B.must C.should D.would6. The biggest problem for most plants, which _ just get up and run away when threatened, is that animals like to eat them. 2007 湖南卷 A. shant
34、B. cant C. neednt D. mustnt 7. She looks very happy. She _ have passed the exam. 2007 江苏卷 I guess so. Its not difficult after all. A. shouldB. couldC. must D. might8. Where is my dictionary? I remember I put it here yesterday. You it in the wrong place. 2007 江西卷 A.must put B.should have put C.might
35、put D.might have put9. As a result of the serious flood, two-thirds of the buildings in the area . 2007 陕西卷A.need rcpairing B.needs to repair C.needs repairing D.need to repair10. I told your friend how to get to the hotel, but perhaps I have driven her ther. 2007 陕西卷A.could B.must C.night D.should1
36、1. The boss has given everyone a special holiday, so we go to work tomorrow. 2007 上海春AcantBmustnt CneedntDshouldnt12. 一What does the sign over there read?一“No person _ smoke or carry a lighted cigarette,cigar or pipe in this area”2007 四川卷Awill Bmay Cshall D. must13. My cats really fat. You _ have gi
37、ven her so much food. 2007 浙江卷 A. wouldnt B. couldnt C. shouldnt D. mustnt 14. What do you think we can do for our aged parents?You _ do anything except to be with them and be yourself. 2007 重庆卷A. dont have to B. oughtnt to C. mustnt D. cant15. Turn off the TV, Jack. _ your homework now?Mum, just te
38、n more minutes, please. 2007 辽宁卷A.Should you be doing B. Shouldnt you be doing C. Couldnt you be doing D. Will you be doing2008年真题福建卷)24. It is usually warm in my hometown in March, but it _ be rather cold sometime. A. must B. can C. should D. would(湖南卷)28. You dont have to know the name of the auth
39、or to find a book. You _ find the book by the title.A. must B. need C. can D. would (江苏卷)35. Im sorry. I _ at you the other day.Forget it. I was a bit out of control myself.A. shouldnt shoutB. shouldnt have shouted C. mustnt shout D. mustnt have shouted(山东卷)24. Thank you for all your hard work last
40、week. I dont think we _ it without you. A. can manage B. could have managed C. could manage D. can have managed(江西卷)26. What a pity. Considering his ability and experience, he _ better.A. need have done B. must have done C. can have done D. might have done(辽宁卷)22. Peter _ be really difficult at time
41、s even though hes a nice person in general.A. shallB. shouldC. canD. must(全国II)17. Liza _ well not want to go on the trip - she hates traveling.A. will B. can C. must D. may(陕西卷)9. What sort of house do you want to have? Something big?-Well, it _ be big-thats not important.A. mustnt B. neednt C. cant D. wont(四川卷)10. Although this _ sound like a simple task, great care is needed. A. must B. may C. shall D. should(浙江卷)11. You _ be hungry already you had lunch only two hours ago!A. wouldnt B. cant C. mustnt D. neednt(北京卷)21. John promised hi