1、情态动词Modal Verbs,情态动词本身不表示动作或状态，只表示说话人认为某件事“能不能/该不该/可不可以做”等的看法。情态动词不能单独构成谓语，必须与动词原形连用，一起构成谓语。没有人称和数的变化。,情 态 动 词 的 形 式,can (could), may (might) dare (dared), shall (should), will (would) must, need, ought to used to，had better，would rather be able to, have to,情态动词表示推测,must, may, might, can, could, 表示推
2、测 must/may/ might/常在陈述句中表示可能性，must比may/ might可能性要强。must maymightcan/ could常在疑问句和否定句中表示可能性cancouldModal verb +v. (be,动词原形）对现在行为的推测Modal verb +have done 对过去行为的推测,表推测时must一般用于肯定句。must的肯定程度比may/might大得多，译为“肯定”a. He must be in his office now for he called me from there five minutes ago.b. Put on more clo
3、thes. You must feel cold with only a shirt on.c. I didnt hear the phone. I must have been asleep.,表推测时may/might 一般用于肯定句。may表示推测的可能性比might大a. She is coming to us. She may/might be our class teacher.b. My mother may be cooking now.c. He seems to know the city quite well. He may/might have been there b
4、efore.,表推测时can/could 一般用于疑问句和否定句。Can表示推测的可能性比could大The young girl cant / couldnt be our new leader. Can/Could this news be true?b. He cant/couldnt be reading in the reading room, for I saw him in the street just now.c. I dont know why she didnt call me yesterday. She cant/couldnt have forgotten my t
5、elephone number.,may/ might have done,可能已经做了某事,must have done,一定已经做了某事了吧,can/ could not have done,不可能做了某事,may/might not have done,可能没做某事,Modal verb +have done,You must have had a terrible dream last night.They may/might have heard the news.He may/might not have been to Beijing.4. He cant have been w
6、orking when I saw him.5. Where can/could he have gone?,should have done/ ought to have done本应该做，但没做should not have done/ ought not to have done 本不应该做，但做了could have done本有能力做，但没做成,You should / ought to have told me the truth early. They shouldnt / oughtnt to have watched TV last night. He could have
7、finished the work but he didnt try his best.,need not have done 表示过去做了没必要做的事情。 You neednt have gone to work yesterday because you were on holiday.didnt need to do过去没必要做某事，实际也没做 The teacher told him that he didnt need to hand in the composition right now, so he decided to write it after the class.,1.
8、 Joe _ (call) his sister last night, but he arrived home so late that he was not able to call her. 2. You _ (scold) him because he had tried his best. 3. -I didnt go to work yesterday because my car broke down.-You _(use) mine. I wasnt using it.4. I was assured by the doctor that my son only had a b
9、ad cold, and nothing was serious. I _ about it.,should have called,(=ought to have done),should not have scolded,(=ought not to have done),could have used,neednt have been worried,Practice,情态动词的其他用法,may/ might:,1. 表示许可（permission）,May / Might I come in?You may / might stay here for as long as you li
10、ke.,回答时，一般避免说Yes, you may或No, you may not.而常用如：Yes, please./ Please dont./ No, you mustnt., The manager said I might look around.,2. 表示祝福,May you succeed!(May you have a) good day!c.f. I wish you good luck!,3.may/ might as well:打算或建议, I may as well start at once.You may/ might (just) as well make a
11、phone call to your Mum first if you want to stay here for the night.,can/ could:,1. 表示能力（ability）,He is eighty but he can still read without glasses. (ability)c.f. He was eighty then but he could ,2. 表示许可（permission）和may相近,You can go at four oclock.Can / Could I park here? Yes, you can. No, you cant
12、.,could表示过去的一般能力，was/ were able to表示过去经过努力而做成了某事的经历，相当于managed to, succeeded in,When he was young, he could read without glasses.He thought he could jump over 1.80 metres, but he was not able to. I ran fast and could catch the bus.(x) I ran fast and was able to catch the bus.,could & was/ were able
13、to,must:,1. 表示必须 (necessity),We must do everything step by step.Teachers must show concern for every student.,mustnt 不准，不许，严禁You mustnt litter everywhere.dont have to/ neednt 没必要Must I leave now? No, you neednt / dont have to.,must:,2. 偏偏, 偏要,When everybody was in bed, he must turn his radio on.As I
14、 was sitting down to supper, the telephone must ring.,must 强调主观原因，have to强调客观原因，因环境所迫，“不得不”,John, you must be back home by ten oclock.I have to be back at school by eight. I have a lot of work to do tonight.As there is no direct transport, you have to change buses.,must & have to,will:,1. 表示意愿(willi
15、ngness),If you will not receive the credit card, I shall pay cash.I have told him many times but he wont listen to me.He said he would lend me some money if I asked him.,2. 表示能力，内在倾向性The hall will seat 1,000.The door wont open.,will / would:,3. 表示请求,邀请(request),主语常为第二人称,Will you help me to put these
16、 books in order?Would you like to play cards with us?Would you mind opening the window?,will / would :,3. 表示习惯性的动作(habit),Boys will be boys.He will always bring a bunch of flowers when he comes to see me.When he was young, he would go to the cafe on the corner after work.In those days, he would work
17、 for hours at night.,should:,1. 表示应该: (ought to),Such a thing shouldnt / oughtnt to be allowed to happen again.They shouldnt / oughtnt to be watching TV now. They should / ought to be doing their homeworkYou should / ought to have told me the truth early.,should:,2. 表示惊异，赞叹，不满等情绪。“居然”,I am sorry tha
18、t he should be in such poor health.It is wonderful that you should have achieved so much in these years.,3. Should 在虚拟语气中的运用,shall:,Shall 主要表示说话者的意愿，而will表示句子主语的意愿。He shall meet me at ten oclock. (I want him to)He will meet me at ten oclock. (He is willing to),You shall not leave the post.,shall:,1.
19、 在陈述句中表示说话人的语气,如:决心,允诺，命令，警告，威胁等。,Nothing shall stop us from carrying out this plan. Tell her that she shall have the book tomorrow. You naughty boy! You shall get what you deserve.,(决心),(允诺),(警告),shall:,. 征求对方的意见 (ask for permission)常用于疑问句，主语通常为第一或者第三人称。,Shall I open the window?Lets have dinner out
20、 tonight, shall we?Shall he come in or wait outside?,had better,Youd better get some sleep.Id better not disturb him.,would rather,He would rather listen to others than talk himself.I would rather not leave here.I would rather you knew that now.,used to,过去常常 I used to drink wine;now I drink beer. We
21、 usednt/didnt use to wear such fancy clothes. Did he use to complain so much?,neednt do sth.,Need he do sth?,need(s) to do sthneed(s) sth(sth) need(s) doing=( needs to be done),doesnt need to do sthdoesnt need sthdoesnt need doing =(doesnt need to be done),Does he need to do sth?Does he need sth?Doe
22、s sth need doing?=(Does sth need to be done?),need,/,need “需要”，作情态动词多用在否定或疑问句中. 作情态动词时没有过去式 Need I attend the meeting tomorrow? You need not hand in the paper this week. need 作实义动词,有第三人称，单复数，后加带 to 的动词He needs some time to think over the question. The desk needs repairing. We need to go over the old
23、 lessons once again.,/,darent do sth,Dare he do sth?,If he dare do sth, he,dares to do sth,doesnt dare (to) do sth,Does he dare (to) do sth?,If he dares to do sth, he,dare,/,dared not do sth,Dared he do sth?,If he dared do sth, he,dared to do sth,didnt dare (to) do sth,Did he dare (to) do sth?,If he
24、 dared to do sth, he,dared,dare “敢”，作情态动词，多用在否定或疑问句中。过去时dared The little girl dare not speak in public. Dare you catch the little cat? Dared he question the order of the commander at that time? dare 作实义动词使用 Do you dare to walk in the dark? He doesnt dare (to) tell the teacher what happened that day.
25、,情态动词专练题,1.Put on more clothes. You be feeling cold with only a shirt on.A. can B. could C. must D. would2. Must I drive to his house and pick up the children? No, _.A. you shouldnt B. you might not C. you neednt D. you mustnt3.You to attend the meeting, but you didnt.A. should comeB. would have com
26、e C. cameD. should have come4.We didnt see Tom at the meeting yesterday. He it.A. mustnt have attendedB. cannot have attendedC. neednt have attendedD. would have not attended5.Tom went on foot, but he by bus.A. might go B. may go C. could have goneD. ought have gone,6.We play chess than bridge. Some
27、 of us dont know how to play bridge.A. had better B. would better C. would rather D. had rather7.There is someone knocking at the door. it be Tom?A. Can B. Must C. Should D. Ought8.There was a lot of time. He .A. mustnt have hurriedB. neednt have hurriedC. could have hurriedD. ought to have hurried9
28、.We didnt study Chemistry last night, but we .A. had studiedB. couldC. should D. could have10.One ought for what one hasnt done.A. not to be punishedB. to not be punishedC. to not punishedD. not be punished,11.May I pick a flower in the garden? .A. No, you needntB. Not, please C. No, you mustntD. No
29、, you wont12.Could I call you by your first name? Yes, you .A. will B. could C. can D. might13.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 not B. may notC. should not D. dont have to14.I didnt see her in the m
30、eeting-room this morning. She at the meeting.A. mustnt have spokenB. shouldnt have spokenC. neednt have spokenD. couldnt have spoken15.I wonder how he that to the teacher.A. dare to sayB. dare saying C. not dare sayD. dared say,16.You take your umbrella. I am sure it wont rain.A. shouldnt B. cant C.
31、 dont have to D. mustnt17.The dog hibernate in winter.A. dont need B. doesnt need to C. needs not to D. needs not18.Look what you have done. You have been careful.A. should B. can C. must D. may20. Lets go to the cinema, shall we? ?A. No, I cantB. Yes, I will C. Yes, thank youD. No, wed better not,2
32、2.Whenever Mother was not here, the children make a lot of noise.A. will B. would C. were to D. were going to23.Why is it so dark. There be a heavy rain coming.A. shall B. may C. should D. will24.Tom is late. What to him?A. should have happenedB. must have happenedC. can have happenedD. would have h
33、appened25.Tom, you play with the knife, you hurt yourself.A. wont, couldB. mustnt, may C. shouldnt, mustD. cant, should,26. “Can you imagine how about it?” “No, I cant.”A. could they know possiblyB. could they possibly knowC. they could possibly knowD. possibly they could know27.Tom full marks, but
34、he was too careless a spelling mistake.A. could gain, to makeB. could have gained, to makeC. could have gained, and madeD. could have gained, as to make28.I wonder how she the drunken sailor the other day.A. dare fighting offB. dared fight off C. dare to fight offD. dared fighting off29. the man the
35、re be our new teacher? He be, but Im not sure.A. May, mustnt B. Can, mayC. Must, cant D. Can, cant30. Someone is knocking at the door. Who it be? It be Tom. He is still in the school.A. can, cant B. can, mustntC. might, could D. might, may,Translation:1我们家里有足够的食物，不需要买什么了。(need)2 你过去没必要把车卖掉，你当时也许可以找我
36、借钱。(neednt)3我们都知道她错了，但没有一个人敢对她说。(dared to)4. 你怎么敢这么跟我说话? (dare)5. 那个餐馆肯定不错，总是顾客盈门。(must),Key for reference1. We have enough food at home so we neednt go shopping now.2. You neednt have sold your car. You might have come to me for money.3. We all knew she was wrong, but none of us dared to tell her.4. How dare you speak to me in such a way?5. That restaurant must be very good. Its always full of people.,
