情态动词 modal verbs1.-Is John coming by train? -He should, but he _ not. He likes driving his car. (2002高考题）A. must B. can C. need D. may 2.It has been announced that candidates(候选人)_ remain in their seats until all the papers have been collected. (2002上海高考题）A. can B.will C. may D. shall 3.-I heard they went skiing in the mountains last winter. (2002北京高考题）-It _ true because there was little snow there.A. may not be B. wont be C. couldnt be D. mustnt be情态动词表示推测不表示推测can could may might shall should must will would ought tohave to dare (darent) need (neednt) used toI darent ask her for a rise. 我不敢请求她加薪.How did you dare to tell her that? I wonder whether he dare stand up in public. I dont know how she dares to wear that dress. Do you need any help?I wonder whether he need send it immediately.I need hardly tell you that the work is dangerous.The garden doesnt need watering at the moment.You neednt finish that work today.可兼做行为动词的情态动词：need 、 dare 情态动词 (+动词原形)行为动词.needdare1.无人称和数的变化; 2.尤其用于： *否定句及疑问句中; *在if/whether之后; *或与hardly, never, no one, nobody连用;3.常以neednt 和 darent 的形式出现;4.dare有其过去时dared.多用于肯定句;(sb.) need to dodare to do (sth.) need to bedone(sth.) need doing 判断正误:How dare you say such a thing?How dare you to say such a thing?He darent to speak English before such a crowd, did he?He darent speak English before such a crowd, dare he?Nobody need to be afraid of catching the disease.Nobody need be afraid of catching the disease.These dishes need be cleaned carefully.These dishes need to be cleaned carefully.These dishes need cleaning carefully.注意对need问句的回答:-Need I finish the work today?-Yes, _.No, _.No, _.you mustyou needntyou dont have toneednt 对其它情态动词的回答:-Shall I tell John about it?-No, you _.-Must we do it now? -No, you _.neednt (dont have to)neednt (dont have to)表示推测情态动词的重要用法. 1. You must be Mr Smith-I was told to expect you here. 2. He must have known what we wanted. 3. We may have read the same report. 4. He cant have slept through all that noise. 5. Theres someone outside-who can it be? 6. What can they be doing? 7. These pills might help to cure your disease. 8. You could be right, I suppose.表示推测情态动词的重要用法.肯定的推测可能的推测否定的推测疑问的推测must/shoul d对将来 对现在 对过去情态动词may, mightcant, couldntcan, could+ V. + V. + have done 常见must be + be doing+ V. + V. + have done+ be doing可以用not表示“可能不” +V. + V. + have done+ be doing+ V. + V. + have done+ be doing1. I dont know where she is, she _ be in Wuhan.2. At this moment, our teacher _our exam papers.这时，我们老师想必在批改试卷。3. The road is wet. It _ last night.(rain)4. Your mother _ for you.你妈妈一定一直在找你。maymust be markingmust have rainedmust have been looking5. Philip _ seriously inthe car accident. 菲利普可能在车祸中受了重伤.6. -Linda has gone to work, but her bicycle is still here.-She _ (go) by bus.7. Mike _ his car, for he came to work by bus this morning.迈克一定还没有找回他的车，因为早上他是坐公共汽车来上班的。may (might) have been hurtmay (might) have gonecant have found高考考题:1. I thought you _like something to read, so I have brought you some books. A. may B. might C. would D. must 2. Where is my pen? I _it. A. might lose B. would have lost C. should have lost D. must have lost3. I didnt hear the phone. I _asleepA. must be B. must have been C. should be D. should have beenB D B 4. -There were already five people in the car, but they managed to take me as well.-It _a comfortable journeyA. cant be B. shouldnt be C. mustnt have been D. couldnt have been 5. Its nearly seven oclock . Jack _be here atany moment.A. must B. need C. should D. couldD C 不同的“肯定”程度可按下列层次排列： He is at home. (事实) He must be at home.（非常肯定的推断） He could be at home.（很可能） He ought to be at home.（很可能） He may be at home.（仅仅可能而已） He might be at home.（或许, 非常不确定） He might not be at home.（也许不在家） He may not be at home. （比might可能） He couldnt be at home.（很可能不在家） He cant be at home.（一定不在家） He isnt at home.（事实） 在不表示推测的情态动词中, 我们要注意以下考点:1. 表示能力、许可的情态动词的用法。2. 表示否定的情态动词的用法。3. shall 和 will 的多种意义的区别。4. 情态动词短语的使用。5. 虚拟语气中情态动词的使用。表示能力: can, could, be able to*be able to 能用于各种时态。can / could 只能表示现在或过去的能力。*was / were able to : “设法做成某事”相当于 managed to do sth. succeeded in doing sth.。1. 表示能力、许可的情态动词的用法。1. A computer _ think for itself; it must be told what to do.A. cant B. couldnt C. may not D. m