1、专题17情态动词和虚拟语气的基本用法一、综述：1. 情态动词，如果没有时态的变化，所有的情态动词都暗示的是“将来时”。You need prepare a long speech. 您需要准备个很长的演讲。You ought to be here by 12 December. 你应该在12月12日前到这。Id rather stay at home. (would rather) 我乐意待在家里。Id like to have a rest. (would like, should like) 我想休息一下。Youd better do something. ( had better) 你最
2、好做点什么。2. 如果是站在现在的角度去的描述过去有可能会发生的事情，必须要用情态动词加完成体。-We didnt see him at the lecture yesterday. 我们昨天没看见他参加讲座。-He couldnt have attended it. 他昨天不可能参加。The watch you gave me is wonderful. You couldnt have given me a better gift than that!您送我的表太好了。您送给了我最棒的礼物！（您不可能送给我比这更好的礼物了!）3. 某些情态动词的过去式不表示过去时，而表达一种委婉的语气。W
3、hat would you like to drink? 您想喝点什么？We might as well have another talk with him next Monday.我们不妨下周一再和他谈一次。二、常用情态动词字典搬家can, may, must, shall, should(ought to), dare, have to, will, used to, need, would like to, please, had better, would ratherCan1)表示能力：Two eyes can see more than one. A blind man cann
4、ot judge colors.2)表示可能性，译成“可以，可能”。We can call for you at nine. You cannot eat your bread and have it.3)表示一时会出现的情况 The English climate can be pretty grim in winter.He is a bad-tempered fellow, but he can be quite charming when he wishes.4)表示许可Can I come in? You can have my seat. I am going now.5) (用于
5、疑问或否定句，表示惊讶、不信) 可能，能够He cant be more than thirty. Can he still be alive after all these years?How can you be so curious about his personal life?Could1). can的过去式a. 表示能力Lucy could run and was a good tennis player. She couldnt understand what I said. b. 表示可能性He said he couldnt come. It was so dark we c
6、ould see nothing.c. 表示许可（用于间接引语）The teacher said we could go to the shop for sweet.2). 用于比较委婉的请求、看法或者疑问，可以与can互换，但是在时态上没有什么差别Could you lend me some money? I could come earlier, if necessary.Why couldnt you wear the brown coat with the blue trousers?3). 用于疑问、否定，表示诧异、不相信，语气比can稍微缓和，与can在时态上没有差别。Oh, ho
7、w could you be so stupid? What could have become of him now?They couldnt have left so soon.4). 用于虚拟语气，表示与事实相反或者可能性不大。If you tried, you could do that work. Even if he had been there he couldnt have helped you.He did nothing for me that my father could have done if he had lived.5). Could + have done用来
8、谈过去的事情。I do not see how I could have done otherwise. We could have started a little earlier.（委婉的批评）We could not have heard them because of the noise from the river.We could have lent you the money. Why didnt you ask me?may1). 表示允许译成“可以”。May I come round in the morning? You may do exactly as you like
9、.2). 表示可能会，译成“或许会，也许会”。猜测It may be a new species. He may be engaged. You may have read some account of the matter.3). 用在状语从句中 Write to him at once so that he may know in time.However much they may desire it they cannot express their feelings.4). 用于祝福，祝愿。（用于正规的场合或书面用语）May you be happy! May God bless
10、you! May all your dreams come true!5). May (just) as well不妨（用于提建议）Well, now you are here, you may as well make yourself useful.We may as well finish the job, now weve got so far with it.5) may well很可能。The team may well have won the football match, but i dont know because I wasnt there.6). Try as you
11、 may, you will get nothing in the end. Might1). May的过去式a. 表示“可以” I asked her if I might call and see her.b. 表示“或许，可能” I supposed her father might like to have here with him for a time.I was careful not to look at him. He might have seen the surprise in my face.我小心翼翼不去看他。他可能看到我脸上吃惊的表情。c. 用于从句中 He die
12、d so that others might live. Try as he might, he could not persuade his friends to go.I wish you were here now that I might thank you in person.2). 替代may,但是语气比较委婉Might I ask for a photograph of you?(可以) He might be waiting for you.（也许）Ive got a lot of books that might interest you.(可能，或许)3). 用于虚拟条件句
13、 If you didnt mind, we might go there.If it hadnt been for the rain, I might have been caught the first train.4). 用于might as well, 表示委婉语气。Perhaps we might as well get round the table. We might as well have gone home as you suggested.Since its a fine day we might as well have a walk in the park.Must1
14、). 表示“必须、一定” You must see the doctor. I must be off. Thank you very much for you lunch.I am afraid I must be going. You mustnt do that again. -Must I come at four oclock?-Oh no, you neednt.2).一定是，用于猜测，比may肯定。Its a quarter past three. He must be in by now.He must have arrived by air.(绝对否定用cant)3).表示s
15、houldought to: You must recognize that we cant allow such behavior.4).表示偏要，硬要 Must you shout so loudly?Must you worry her with questions, just when she is busy cooking dinner?Shall1). 第一人称将来时。We shall read about this tomorrow.(shant)2). 用于第一、三人称表示征求意见 Shall I turn on the light? Shall the boy wait?3)
16、. 用于各种人称表示许诺、威胁、命令、规定I promise anyone shall have a reward if he can open the window.You shall hear everything directly you come. She shall not stay under my roof!If you children wont do as I tell you, you shant go to the party.Members shall enter the names of their guests in the book provided.All fo
17、reign residents shall have reported to the nearest police station.4). 用在某些从句中，和should作用差不多。(不倾向替换)We demand that the rich shall pay for them. My mother is determined that I shall stay with Jack.Should1). 第一人称过去将来时。We thought we should never see you again.2). 用于各种人称，表示应该 I should (ought to)write some
18、 letters tonight. Why should the boy answer for the mistakes? You are right. I should have thought of that.Often, when he should have been doing something that was given him, he wasted his time drawing pictures.3). 用于各种虚拟形式，句型需要 He suggested that he (should) come to Paris.It will be better that he s
19、hould be out of France. It is important that he should go to the art school. 4). 用在某些句子中，表示差异、不以为然 It seems so unfair that this should happen to me.It wasnt right that such near neighbors should not know one another. 5). 用于虚拟条件句. Should you be passing, do come and see me.Should I be free tomorrow, I
20、 will come. 6). 用于第一人称，表示态度谦和 I should be glad to talk to him.There are a lot of things that I should have liked to ask you.7). 表示按一定常理估计可能会发生的事情。I think she should be there by now.We neednt get ready yet, the guests shouldnt come for another hour.Will1). 各种时态的将来时。Who will be on duty this Saturday?2
21、). 用于第二人称，表示请求 Will you tell her that I am at Mrs. Michael Monts?Wont you sit down?3). 用于各种人称，表示愿意，I will pay you at the rate you ask. She wont see her boyfriend right now.4). 用于各种人称，表示倾向、习惯、译为“总是会、不肯等”A wise man change his mind, a fool never will.The window wont open. A drowning man will catch at a
22、 straw.Oil and water wont mix.5). 用于各种人称,表示决心 We will not have anything said against her.6).表示猜测，可以译成“想必，一定是” He will be there!Sorry to be so late. You will have been waiting for some time.Would1). 各种人称的将来时。She didnt know when she would be seeing any of them again.2). 委婉的语气, 用will也可以，在时态上没差别。Would y
23、ou please hand me the papers there? You would never do anything to hurt me.3). 用于虚拟，表示假象与事实相反或不太可能。If people studied, they would learn. I would have written before, but I have been ill.4). 表示过去一贯的习性 He would sit there for hours sometimes, doing nothing at all.Need常用于否定句或疑问句中1). 用于否定或疑问句：I think you
24、need not be impolite to her. So you neednt hurry with your meeting.You neednt have told him that. I dont believe you need worry.He was told that he neednt do it. =He was told that he didnt need to do it.Need you go yet? Yes, I must. I asked him whether he need go. 2). 偶尔用于肯定句。There was another hour
25、before I need go out into the cold. Dare常用于否定句或疑问句中。作为情态动词，dare后面可以变过去时，但是没有单三的形式。He dared not go near Ruths neighborhood in the day time.No one dared ask of it. I scarcely dare think of it.She dare not say what she thinks. How dare you say that?Jump if you dare. Dare you have tried the food if you
26、had known it was a worm?三、虚拟语气-简单的说就是把“实际时态”成“过去式”。 口诀：一个if，两个要是要不是，三种句型，四种词汇，希望你记住一个If （as if）If I were you, I would do something. ( If I am you, I will do something.)If I had been there, I would have bought the bargain. ( If I was there, 情态动词加完成体)两个“要是”“要不是”but for(要不是), without(要不是), if only(要是怎么
27、样就)otherwise(要不然)But for my mother, we couldnt have enjoyed such a wonderful lunch. If only I could speak English, but I didnt learn it in my junior middle school. Had it not been for the storm, we would be at home enjoying heavy meals now. 要是我会说英语就好了，但是我在初中没学过。三种句式 It is time that you did something
28、. Id rather you did something. Would you mind if I did something?( Do you mind if I do something?)四种词汇 省略should 一坚持 insist 二命令 order, command 三要求 require, demand, request (ask, urge表示要求时也行)四建议 advise, suggest recommend, proposeI suggested the boy should not be sent to school. My suggestion that the
29、trees be planted at once was refused. It is a pity that somebody should do. It is strange/ impossible, important, necessary that somebody should do最后希望(wish)你记住I wish I could fly.我希望我会飞。四、实战演练。1. Stranos team found that they _(can)create a faint light for three-and-a-half hours. 2. You will make mis
30、takes, time and time again. Rather than getting caught up in how you _(do) better, why not offer yourself a compassionate (有同情心) response? 3. Heres a handful of ways that _set you in the right direction. 4. In fact, anyone wishing to try race walking _probably first consult a coach or experienced ra
31、cer to learn proper technique. 5. Thus, the keyboard can determine peoples identities, and by extension, whether they be_ given access to the computer. 6. I cant find my purse. I_(leave)it in the supermarket yesterday, but Im not sure. 7. The workers were not better organized, otherwise they _(accom
32、plish) the task in half the time.8. There is a good social life in the village, and I wish I_ (have)a second chance to become more involved. 9. I work with Volunteers for Wildlife, a rescue and education organization at Bailey Arboretum in Locust ValleyTrying to help injured, displaced or sick creat
33、ures _be heartbreaking; survival is never certain 10. Handing out sliced oranges to bloodthirsty kids _be as exciting as watching your own kid score a goal. 11. These techniques allow you to quickly organize your thoughts as well as to make sure you _(will) be correctly answering the question 12. Dr
34、ayton is optimistic that in ten years Ashoka_(will)be making really serious，practical progress in bringing about social change by hanging the way we look at economic development13. Truly elegant chopsticks might (make) of gold and silver with Chinese characters. 14. What a pity! You missed the sight
35、seeing, or we _(have) a good time together. 15. Erin had gone beyond what almost anyone_(do), finding my house on a bitterly cold night, and for that I was extremely grateful. 16. Now, a new studysuggestsgetting benefits from exercise _(not have)to be that demanding. 17. Carol Harveysuggeststhat cyc
36、lists _(ask) to ride on their own lanes. 18. The manager put forward asuggestionthat we _(have)an assistant. 19. By the time these solutions become widely available, scammers_ (move) onto cleverer means.20. If we had caught the flight yesterday, we would be enjoying our holiday on the beach now._(倒装
37、), we would be enjoying our holiday on the beach now.21. At some time in the past Yellowstone _(must blow)up with a violence far beyond the scale of anything known to humans.答案:1.could, 2.could have done, 3.will, 4.should, 5.should, 6.could have left, 7. would have accomplished, 8.had, 9.can, 10.can可以表示“有时候会”9.10均是此用法, 11.will be doing 可以表示马上要做，而非将来进行,12. will be doing还可以按一定逻辑将来注定会发生的事情，也不是将来进行时, 13. be made, 14. could/would have had, 15. wouldhave done, 16. doesnt have, 17.be asked, 18.should have, 19.willhave moved, 20.Had we caught the flight yesterday, 21. must have blown
