1、Grammar,modal verbs II,主要情态动词,Can, couldMay, mightWill / wouldShall / should / ought toMust / have toNeedDare,can, could 和be able to的用法,She can/be able to sing the song in English.This machine can make you feel comfortable.,1.can, be able to都可表示“能力”,Can的主语是人或物,be able to的主语是人,Although the soldier wa
2、s badly wounded, he was able to tell what had happened.She ran fast but she couldnt /wasnt able to catch the bus.,3.表示特定的某一过去能力或表示成功地做了某事时，只能用was/wereableto，不能用could。,HewasabletoleaveEuropebeforethewarbrokeout. Hewasabletoswimhalfwaybeforehegottired.,表示过去的能力,Could I have a look at your notebook?Yes
3、, you can./No,youcant.,4.could不表示时态 ,表示委婉的请求，（注意在回答中不可用could）。,Can this news be true?How can you be so foolish? It cant be Mary. She has fallen ill.,5.表示“惊异,怀疑,不相信”的态度(主要用于否定句,疑问句和感叹句中),Linda didnt catch the train. She could have caught it. Dontworry. Theycouldhavejustforgottentophone.,6.表示推测，译为“可能、
4、或许”，can常用于否定句(意思是不可能已经)和疑问句；could除用于否定句及疑问句外,还可用于肯定句(意思是那时可能;本来可以)。,may和might,-May I use your pencil?,-Yes, you may./ No, you mustnt.,1. may和might 用于一般问句中表示委婉的请求,肯定回答用may,否定用mustnt,She may not be working now. John might be at home now.,2. may和might表示“可能性”, may/might + v 指现在或将来可能发生的动作情况。might暗示的可能性更小
5、,She may/might have gone to the cinema. They may/might not have received our telephone.,3.对过去发生的事情的可能性作出判断用may/might have done,用might比用may的可能性更小,May you succeed! MayGodblessyou!,4.may放在句首祈使句，表示祝愿。,Will 和 would,If you will help me with my English, I will be very happy. I promised that I would do my b
6、est.,1.will和would表示意愿、意志，可用于各种人称,Will you tell him the news as soon as he comes back？ Would you please speak again more slowly？,2.在疑问句中,will用于第二人称,表示请求或征求意见,would则语气更委婉,shall ,should 和ought to,You shall do as I say. (命令) Tell him that he shall have the book tomorrow. (允诺) Nothing shall stop me doing
7、 it. (决心),1.shall用于第二、三人称表示允诺、警告、命令、决心等。,Shall I open the window for you？（征求意见） Shall he fetch some water for you？（请求）,2.在疑问句中,用于第一、三人称，用来表示请求或征求意见。,Young people should learn how to use computers. Every citizen ought to obey law. You ought not to go.,3. should常表示劝告、建议、命令，与ought to意义相近，但ought to多表示责任
8、、义务，语气强烈。在疑问句中通常用should代替ought to。,You should/ought to have told her the truth earlier. She shouldnt have left without saying a word.,4.should/ought to have done表示责备或批评,意为“本应该做到但没有做到”,用于否定则表示“本不该但”ought to的语气更强烈.,must 和haveto,1.Must用于一般问句中,肯定回答用must否定式用neednt或dont have to，做“不必”,mustnt表示“禁止，不允许”, Mus
9、tIfinishallassignmentsatatime?,Yes, you must. No,youneednt.,I dont like this TV set. We must buy a new one. There was no more bus. They had to walk home.,2.表示“必须”这个意思时，must和haveto稍有区别。must着重说明主观看法，haveto强调客观需要。另外，haveto能用于更多时态。,Youmustbethenewteacher. Hemustbejoking. Thereisnobodyhere.Theymusthaveal
10、l gonehome.,3.must表示对某人某事的猜测，作“准是”，“一定” ，一般用于肯定句中。对过去发生的事情作肯定判断用must have done,Need I do ? Yes, you must. No, you neednt.,-May I use your pencil?,-Yes, you may./ No, you mustnt., MustIfinishallassignmentsatatime?,Yes, you must. No,youneednt.,dare & need,Must +have done 表示对过去已经发生的行为进行推测，意为“想必/准是/一定作了
11、某事”。,can/could+have done表示对过去的行为的怀疑和不肯定，通常用在否定句和疑问句中。,could(不用can)+have done,在肯定句中表示“本来能够而没能”，具有婉转的批评和责备之意。,表示推测情态动词的重要用法.,should/ought to+have done用于肯定句时，表示“本该做某事而实际上没做”，用于否定句时，则表示“不该做的事反而做了”。,might（不用may）+have done表示“本来可能”，但实际上没有发生的事。另外，还可表示“本来应该或可以做某事”之意，含有轻微的责备语气。,neednt +have done表示做了本来不必去做的事。,
12、1.He must have gone to Beijing. 他一定已经去北京了。2. It couldnt have been Mr. Green. He has gone to New York. 那不可能是格林先生的，他已经去北京了。3 You could have told me earlier. 你本该早点告诉我的。,4.You should have told him a week ago.你本来应该在一周前告诉他的。5. You might have come earlier.你本可以早点来的。（但没有这样）6.She neednt have gone to the stati
13、on yesterday.昨天她本不必到火车站去的.（昨天她去了）,巩 固 练 习,1.Oh, Im not feeling well in the stomach. I _ so much fried chicken just now.A. shouldnt eat B. shouldnt have eaten C. mustnt eat D. mustnt have eaten2.-Did you go to the movie the day before yesterday? -No. We _, but we decided not to.A.should have gone B.
14、could go C. should go D. could have gone,B,A,3.Im rather surprised you havent reported him to your teacher. In my opinion, you _ this as soon as you found out he was cheating. must have done B. might have done C. should have done D. could have done,C,Practice 1: 高考考题专练1. I thought you _like somethin
15、g 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 _asleep A. must be B. must have been C. should be D. should have been,B,D,B,4. -There were alrea
16、dy five people in the car, but they managed to take me as well. -It _a comfortable journey A. cant be B. shouldnt be C. mustnt have been D. couldnt have been 5. Its nearly seven oclock . Jack _be here at any moment. A. must B. need C. should D. could,D,C,6. -Did the train arrive in time?-No. It _ tw
17、o hours ago.A. must have arrived B. ought to have arrivedC. must arrive D. ought to arrive7. Must I drive to his house and pick up the children? No, . A. you shouldnt B. you might not C. you neednt D. you mustnt,B,C,8. We didnt see Tom at the meeting yesterday. He it. A. mustnt have attended B. cann
18、ot have attended C. neednt have attended D. would have not attended,B,9. Two years ago, my husband bought me a bicycle. If you live in town, it is often faster than a car and you worry about parking. A. must notB. may not C. should notD. dont have to,D,10. You _ such a long composition. The teacher
19、only asked for 300 words. You have written 600.A. mustnt have written B. couldnt have writtenC. neednt have written D. do not have to write,C,1.-There were already five people in the car but they managed to take me as well. -It _a comfortable journey. ( ) A. cant be B. mustnt have been C. shouldnt b
20、e D. couldnt have been,D,2.The fire spread through the hotel very quickly but everyone _ get out. ( ) A. had to B. would C. could D. was able to,D,EXERCISES,4. Peter _ come with us tonight, but he isnt very sure. must B. can C. may D. will,C,5. - Could I call you by your first name? - Yes, you_. A.
21、will B. could C. may D. might,C,6. Sorry, I m late. I _ have turned off the alarm clock and gone back to sleep again. might B. should C. can D. will,A,8. -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,B,9. With so much
22、 work on hand, you _to see the game last night. A. mustnt go B. could have goneC. shouldnt go D. shouldnt have gone,D,10.Johnny, you _play with the knife, you _hurt yourself. ( )A. wont ; cant B. mustnt ; mayC. shouldnt ; must D. cant ; wouldnt,B,11.There is no light in the dormitory. They must have gone to the lecture, _? ( ) A. didnt they B. dont they C. mustnt they D. havent they,D,12. I missed the bus, so I _ go home on foot. A. must B. may C. can D. had to,D,
