1、Grammar,Grammar,Modal verbs,1. 情态动词有一定的意义，只表示期待或估计某事的发生，不能表示正在发生或已经发生的事情。 2. 没有人称和数的变化，即情态动词第三人称单数不加-s。 3. 不能独立使用，它和后面的动词构成谓语。 4. 情态动词 除ought 和have 外，后面只能接动词原形 5. 情态动词没有非谓语形式，即没有不定式，分词，等形式。,只作情态动词的 can/could, may/might, ought to, must,可情态可实义的 need, dare/dared,可情态可助动词的 shall/should, will/would,相当于情态动
2、词的 have to, used to,情态动词的语法特征,1.So he can carry heavy books. 2. He couldnt open the door by himself. 3. Could you open the door, please?,The modal verbs “can” and “couldnt” mean ones ability to do something. They are similar to “be able to do something”. “could” in the third sentence means making a
3、request,Must , can/could, may/might 的用法,must,1.Must 表示推测时， 只能用于肯定句。,must do 对一般时的肯定推测,must have done 对过去发生的事情作出的肯定判断,must be doing 对现在的动作进行肯定推测,他们买了一辆新车。 他们一定很有钱,They have bought a new car. They must have a lot of money.,他现在一定在看小说,He must be reading novels now.,路是湿的。昨天晚上一定下雨了。,The road is wet. It mu
4、st have rained last night.,can/could,1. can /could 表示推测时，只能用在否定句或疑问句中。,Its so late. Can Tom be reading?,这么晚了，汤姆还在看书吗？,这个人不可能是玛丽， 她生病了。,It cant be Mary. She has fallen ill.,她不可能在说谎。,She couldnt be telling lies.,2. can/could not have done 对过去发生行为进行推测:不可能做某事,刚才我还看见他了， 所以他不可能出国的。,I saw him just now so h
5、e couldnt have gone abroad.,门是锁着的， 所以她不可能在家。,The door was locked，,so she couldnt have been at home.,3. can/could have done “本可以，本可能做某事”用于肯定句中，表示对过去发生的事情做出的判断，,你本来可以考的更好。,You could have had a better mark.,may/might,1.May/might表示推测时，只能用于陈述句，表示对现在或将来要发生的动作把握不大。(maymight),她们明天可能会到这里来。,They may come here
6、 tomorrow.,他们可能还在等我们呢。,They may be still waiting for us.,2.might 可用于指过去的行为或者表示可能性更小。,他也许在作功课吧。,He might be doing his homework now.,我问他我是否可以离开。,I asked him if I might leave.,I asked him “May I leave now?”,3.might/may have done,表示对过去发生的动作进行可能性推测，,他可能去医务室了。,He may have gone to the clinic.,他可能已经从报纸上知道这个
7、消息了。,He might have read about the news in the newspaper.,Will /Would you do? 表请求，表意志，愿望，决心would表过去反复发生得动作或某种倾向“总是,总要” used to表过去常常（现在已没有这种习惯）“过去常常” used to 可于状态动词连用 would不可以 eg. He used to be a quiet boy. ( ) He would be a quiet boy. ( ),will/would,If you will help me with my English, I will be very
8、 happy.,I promised that I would do my best.,You shall do as I say. (命令),1.在陈述句中,shall用于二、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）,2.在疑问句中,用于一、三人称，用来表示请求或征求意见。,shall ,should 和ought to,Tell him that he shall have the book tomorrow. (允诺),Nothing shall stop me doing it. (决心),Shall he fe
9、tch some water for you？（请求）,Young people should learn how to use computers.,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、义务，语气强烈。,Every citizen ought to obey law.,You ought not to go.,You should/ought to have told her the truth earlier.,She shouldnt have left without saying a word.,4.should/oug
10、ht to have done表示责备或批评,意为“本应该但”,ought to的语气更强烈,用于否定则表示“本不该但”,5.Should用于可能性推测时,表“应该，很可能”,They left at 5:30. They should get there now.,- Need he start from the beginning? - Yes, he must. - No, he neednt/doesnt have to.,1.作情态动词时,仅用于否定或疑问句,后接动词原形,表“需要”,need,You neednt return the book now.,2.neednt have
11、 done 表示做了本不必要做的事情,意为“本不必要”,Our color TV set is still good enough. You neednt have bought a new one.,3.Need作实义动词时,表示“需要”，有人称、时态、和数的变化,He needs to finish it this evening. The classroom needs cleaning.,巩 固 练 习,1.Oh, Im not feeling well in the stomach. I _ so much fried chicken just now. A. shouldnt ea
12、t B. shouldnt have eaten C. mustnt eat D. mustnt have eaten 2.-Why hasnt Jane arrived yet?-She _ again in the morning? A. shouldnt have overslept B. may have turned off the alarm clock C. must have no one t o call her D. should have someone to wake her up 3.-Did you go to the movie the day before ye
13、sterday?-No. We _, but we decided not to. A.should have gone B. could go C. should go D. could have gone,B,B,A,4.As it turned out to be a small house party, we _ so formally. neednt dress B. didnt have to dress up C. Might not have dressed up D. neednt have dressed up 5.Im rather surprised you haven
14、t 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,D,C,1.作为情态动词用，常用在否定句和疑问句中。,Dare (need) +S +V S + darent (neednt) +V,I darent walk through the forest at night. Dare you walk thr
15、ough the forest at night? You neednt return the book now. Need he go yesterday?,可兼做行为动词的情态动词：need 、 dare,2.作实义动词用，常用在肯定句中, 有人称、时态、和数的变化,He needs to go there himself. He has grown up,we dont need to worry about him.,3.Sth (sb) need( want, request)+ doing/ to be doneThe house needs cleaning/ to be cle
16、anedThe boy needs sending to the hospital at once.,句型 时态 动词 情态动词dare 实义动词 dare 肯定句 现在时 dare do dare/dares to do 过去时 dare do dared to do 否定句 现在时 darent/dare not do do/does not dare (to) do 过去时 dared not do did not dare (to) do 疑问句 现在时Dare he do? Do you/Does he dare (to) do? 过去时 Dared he do? Did he da
17、re (to) do,2.I wonder how he_that to the teacher.A. dare to say B. dare sayingC.not dare say D.dared say,D,4.As it turned out to be a small house party, we _ so formally. A neednt dress B. didnt have to dress up C. Might not have dressed up D. neednt have dressed up,D,1.判断正误:,How dare you say such a
18、 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?,Exercises,Nobody need to be afraid of catching the disease.Nobody need be afraid of catching the disease.,These dishes need be cleaned carefully.These
19、 dishes need to be cleaned carefully.These dishes need cleaning carefully.,用情态动词完成句子 1.Youve been working all day. You_ be very tired. 2.(The doorbell rings) I wonder who that is. It _ be Lisa. Shes still in the library at this time. 3.It is a long time since we met last time. You _ come and see us
20、more often.,must,cant,should,4.I havent decided where Im going for my holidays. I _ go to Australia. 5.My fathers birthday is ccoming. What _ I get him? 6.Why dont you try on this dress? It _ look nice on you.,may,shall,will,-_ I go out to play, mum?-No, you_. You should do your homework first.A. Mi
21、ght; wouldntB. May; had better notC. Must; mustntD. Need; mustnt,B,2. -Where is Emma?-I cant say for sure where she is, but she_ be out shopping.A. canB. shouldC. mustD. may,D,3. The room is in a terrible mess; it _ cleaned.A. cant have beenB. couldnt beC. may have beenD. would be,A,4. How_ you say that you really understand the whole story if you have covered only part of the article?A. canB. mustC. needD. may,A,5. There _ be any difficulty about passing the road test since you have practiced a lot in the driving school.A. mustntB. shantC. shouldntD. neednt,C,Thanks a lot!,
