情态动词有一定的意义

1、GrammarModal verbs1. 情态动词有一定的意义，只表示期待或估计某事的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。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没有人称和数的变化，即情态动词第三人称单数不加加-s。 3. 不能独立使用，它和后面的动词构成谓语。不能独立使用，它和后面的动词构成谓语。4. 情态动词情态动词 除除ought 和和have 外，后面只能接动词原外，后面只能接动词原形形5. 情态动词没有非谓语形式，即没有不定式，分词，情态动词没有非谓语形式，即没有不定式，分词，等形式。

2、等形式。 只作情态动词的只作情态动词的 can/could, may/might, ought to, must可情态可实义的可情态可实义的 need, dare/dared可情态可助动词的可情态可助动词的shall/should, will/would相当于情态动词的相当于情态动词的have to, used to情态动词的语法特征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 “

3、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 request.Must , can/could, may/might 的用法的用法must1.Must 表示推测时，表示推测时， 只能用于只能用于肯定句。肯定句。must do 对对一般时一般时的肯定推测的肯定推测must have done 对对过去发生的事情过去发生的事情作出的肯定判断作出的肯定判断mu

4、st be doing 对对现在的动作现在的动作进行肯定推测进行肯定推测 他们买了一辆新车。他们买了一辆新车。 他们一定很有钱他们一定很有钱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。路是湿的。昨天晚上一定下雨了。The road is wet. It must have rained last night.can/could 1. can /could 表示推测时，只能用在表示推测时，只能用在否定

5、句或疑问句否定句或疑问句中中。Its so late. Can Tom be reading?这么晚了，汤姆还在看书吗？这么晚了，汤姆还在看书吗？这个人不可能是玛丽，这个人不可能是玛丽， 她生病了。她生病了。It cant be Mary. She has fallen ill.她不可能在说谎。她不可能在说谎。She couldnt be telling lies.2. can/could not have done 对对过去发生过去发生行为进行推行为进行推测测:不可能做某事不可能做某事刚才我还看见他了，刚才我还看见他了， 所以他不可能出国的。所以他不可能出国的。 I saw him just

6、 now so he couldnt have gone abroad.门是锁着的，门是锁着的， 所以她不可能在家。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，本可能做某事本可以，本可能做某事”用用于于肯定句肯定句中，表示对中，表示对过去发生的事情过去发生的事情做出的判断，做出的判断， 你本来可以考的更好。你本来可以考的更好。You could have had a better mark.may/might1.May/might表示推测时，只能用于陈述句，

7、表示对现表示推测时，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。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。她们明天可能会到这里来。They may come here tomorrow.他们可能还在等我们呢。他们可能还在等我们呢。They may be still waiting for us.2.might 可用于可用于指过去的行为或者表示可能性更小指过去的行为或者表示可能性更小。他也许在作功课吧。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。我问他我是否可以离开。I asked him

8、 if I might leave.I asked him “May I leave now?”3.might/may have done,表示对表示对过去发生的动作过去发生的动作进行进行可能性推测，可能性推测， 他可能去医务室了。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消息了。他可能已经从报纸上知道这个消息了。He might have read about the news in the newspaper.Will /Would you do? 表请求，表意志，愿望，决心表请求，表意志，愿望，决心would表过去反复发生得

9、动作或某种倾向表过去反复发生得动作或某种倾向“总是总是,总要总要”used to表过去常常（现在已没有这种习惯）表过去常常（现在已没有这种习惯）“过去常常过去常常”used to 可于状态动词连用可于状态动词连用would不可以不可以eg. He used to be a quiet boy. ()He would be a quiet boy. ( ) will/wouldIf you will help me with my English, I will be very happy. I promised that I would do my best.You shall do as I

10、 say. (命令命令)1.在陈述句中在陈述句中,shall用于二、三人称表示允诺、警告、用于二、三人称表示允诺、警告、命令、决心等。命令、决心等。Shall I open the window for you？（征求意见）？（征求意见）2.在疑问句中在疑问句中,用于一、三人称，用来表示请求或征用于一、三人称，用来表示请求或征求意见。求意见。shall ,should 和和ought toTell him that he shall have the book tomorrow. (允诺允诺)Nothing shall stop me doing it. (决心决心) Shall he fet

11、ch some water for you？（请求）？（请求）Young people should learn how to use computers. 3. should常表示劝告、建议、命令，与常表示劝告、建议、命令，与ought to意意义相近，但义相近，但ought to多表示责任、义务，语气强烈。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 w

12、ithout saying a word.4.should/ought to have done表示责备或批评表示责备或批评,意意为为“本应该本应该但但”,ought to的语气更强烈的语气更强烈,用于否定用于否定则表示则表示“本不该本不该但但”5.Should用于可能性推测时用于可能性推测时,表表“应该，很可能应该，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

13、时作情态动词时,仅用于否定或疑问句仅用于否定或疑问句,后接动词原形后接动词原形,表表“需需要要”need You neednt return the book now.2.neednt have done 表示做了本不必要做的事情表示做了本不必要做的事情,意为意为“本不必要本不必要”Our color TV set is still good enough. You neednt have bought a new one.3.Need作实义动词时作实义动词时,表示表示“需要需要”，有人称、时态、和，有人称、时态、和数的变化数的变化He needs to finish it this even

14、ing. The classroom needs cleaning.1.作为情态动词用，常用在否定句和疑问句中。Dare (need) +S +VS + darent (neednt) +VI darent walk through the forest at night.Dare you walk through 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：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H

15、e 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 done The house needs cleaning/ to be cleaned The boy needs sending to the hospital at once. 句型句型 时态时态 动词动词 情态动词情态动词dare 实义动词实义动词 dare 肯定句肯定句 现在时现在时 dare do dare/dares to do 过去时过去

16、时 dare do dared to do 否定句否定句 现在时现在时 darent/dare not do do/does not dare (to) do 过去时过去时 dared not do did not dare (to) do疑问句疑问句 现在时现在时Dare he do? Do you/Does he dare (to) do? 过去时过去时 Dared he do? Did he dare (to) do 2.I wonder how he_that to the teacher. A. dare to say B. dare saying C.not dare say D.

17、dared sayD4.As it turned out to be a small house party, we _ so formally.A neednt dress B. didnt have to dress upC. Might not have dressed up D. neednt have dressed upD1.判断正误判断正误: 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?H

18、e 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. 用情态动词完成句子用情态动词完成句子1.Youve been wor

19、king 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 more often.4. I havent decided where Im going for my holidays. I _ go to Australia.5. Who was the ma

20、n talking with your teacher? -Im not sure. It _ be her brother.6. When he was there, he _ go to that coffee shop at the corner after work every day.7. You _ play the piano while the baby is sleeping.8. Tom, please lend me a hand. My drawer _ not openmustcantshouldmaymightwouldmustntwill 1The flower

21、is dead. I _ it yesterday. Ashould water Bmust water Cshould have watered Dmustnt have watered 2What time ought I _? Aarrived Barriving Carrive Dto arrive 3He _ speak to his mother like that. Aought not to Bdoesnt ought to Cnot ought to Dought to not 4I dont think wed better _ it any more. Adiscuss

22、Bdiscussing Cto discuss Ddiscussed 5You ought to _ him, but you didnt. Ahelp Bhelped Chelping Dhave helpedC D A A D 1.-Excuse me, but I want to use your computer to type a report.-You _ have my computer if you dont take care of it.A. shant B. might not C. neednt D. shouldntA2. -When can I come for t

23、he photos ? I need them tomorrow afternoon. -They _be ready by 12 : 00 . A. can B. should C. might D. needB3. With so much work on hand, you _to see the game last night. A. mustnt go B. could have goneC. shouldnt go D. shouldnt have goneD1. - Will you go skating with me this winter vacation? - It _

24、. ( 2002上海上海)all depended B. all dependsA. C. is all depended D. is all depending解析：答案解析：答案B。It all depends 是是“不确定不确定”、“看情况看情况”的意思。的意思。高考链接B2. I failed in the final examination last term and only then _ the importance of studies.( 2004重庆重庆 )A. I realized B. I had realizedC. had I realized D. did I r

25、ealize解析：答案为解析：答案为D. 句首为句首为“only + 副词副词”时，时，句子要用部分倒装语序；根据语境应为一句子要用部分倒装语序；根据语境应为一般过去时态。般过去时态。D3. - I would never come to this restaurant again. The food is terrible! - _ . ( 2004全国全国 ) A. Nor am I B. Neither would I C. Same with me D. So do I 答案答案B B。第一个句子使用了。第一个句子使用了would, would, 用用neitherneither表示附

26、和的意义时，助动词应与上表示附和的意义时，助动词应与上文一致。文一致。BWhen you are very sure of something, you use must in positive sentences and cannot or cant in negative sentences.e.g. You must be Jeanne. Im Mathilde Loisel. We used to know each other very well. It cant be true! I dont believe it.When you are quite sure about som

27、ething, you use can. e.g. Attending a ball can be exciting.Practice 1When you think that something is possible, but you are not very sure, you use could, may or might.e.g.You could borrow some jewellery from your friend Jeanne, who is married to a rich man.You may not know that the necklace I return

28、ed is not the one that I had borrowed.Dont you have a friend who might lend you some jewellery? 1. 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。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

29、直在找你。你妈妈一定一直在找你。maymust be markingmust have rainedmust have been looking5. Philip _ seriously in the car accident. 菲利普可能在车祸中受了重伤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，因为早上他是坐迈克

30、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。公共汽车来上班的。may (might) have been hurtmay (might) have gonecant have found用情态动词完成句子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 las

31、t time. You _ come and see us more often. mustcantshould4.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.mayshallwill7. “Who was the man talking with your teacher?” “Im no

32、t sure. It _ be her brother.”8.I dont know when the guests _behere. They _ arrive at any time. mightwillcould 2. A: _ Xiao Feng find the origin of Easter from that book? B: No, he _. 1. A: _ you like to go to a special event with us on Saturday? B: Yes, I _ _.Wouldd like to go with you on SaturdayCouldcouldnt find itExercise 3. A: _ I go with my friend to the harvest festival? B: Yes, you _ _. 4. A: If I want to be a doctor _ I study science? B: Yes, you _. should study scienceMay