情态动词用法小结（复习） 一、各个情态动词用法归纳 can和 could 1 . 表示“能力” I can swim , but my sister can't. 2．表示“许可”、“请求” Can I go with you ? (请求)　　 Father said I could go to cinema. (表示过去的许可)　　 You cannot smoke in the meeting room. (cannot 表示“禁止”)　 Could I use your phone?Yes, of course you can. 肯定回答，不能用could ，一般是—Yes, please.— Thanks. 3．表示“理论上或逻辑上的可能” Anybody can make mistakes. (只表示理论上的可能性)　　 An accident can happen if you do this. (表示事情肯定会发生) 4．“猜测”（主要用于否定句和疑问句）： He can't be at home. (否定句)　 Can the news be true ? (疑问句)　

may 和might 与be able to 的区别： can 只有现在和过去时态，强调能力； Mary can play the piano .She has been able to play it since she was 5. Yesterday I was able to get home before the heavy rain. 　may 和might 1．表示“许可” You may take a walk.　　 Students may not make noise in the library. (may not 表示不许可或禁止) May I come in? 否定回答No, you mustn't. /cannot. 也可以 may not 肯定回答sure, certainly, of course Might I trouble you for a light? "You may indeed." 2.表示"事实上的可能性" It may rain tomorrow.　(表示可能会发生)　 Electric irons could be dangerous,they might give you a severe shock. 3.“预测” Sam might have taken the money, but it seems unlikely.

must shall 1.表示“必须”、“务必”： We must obey orders. Must I pay now ? 肯定回答 Yes, you must　 否定回答 No, you needn't 或 No, you don't have to 2.表示"预测" (必定，必会) 一般用于肯定句。可用于否定一般疑问句。 There must be a mistake. Mustn't there be another reason for his behavior? 3. 偏偏 Our boy must do the opposite to what we ordered. Just when I was busy , she must come and chat shall 1.用于第一、三人称，表示征求对方的意见 Shall we talk?　　 Shall he come to see you ? 2.用于第二、三人称，表示"命令、允诺、警告、决心"等 Each member shall wear a name card. No one shall stop me.　 You shall have the book when I finish reading it. He shall get his allowance.

Should Will和 Would 1.表示“必须”： I should answer his letter as soon as possible.　　 You shouldn't judge a man always by the clothes. (shouldn't劝告) 2.猜测，“估计 应该” That should be Janet coming upstairs now. 正在上楼的该是珍妮特。 Will和 Would 1.表示“意愿” I will call you as soon as possible.　 Who will do the job ? He would not let me try .　 2..表示“请求” Will you kindly tell me the way to the post office ?　 Would you give me your address ? (用 would 比 will 表示更客气) 3.表示“预测”或“习惯性”： That would be his mother.　(would be 表示肯定是)　 He will sit there hour after hour looking at the river.　 　He would come to see me when he was in London.

ought to used to 与would的区别 should 和ought to的区别 used to表示过去情况与现在不同; People used to think that the earth was flat. She would go out for a walk in the morning when she was in the country. ought to　 1.表示“应该” You ought to go to see the doctor. (ought to 的语气比must 弱) 　You oughtn't (ought not) to smoke so much. Ought you to smoke so much? 　　 2.表示“预测”，婉转,比must语气弱 They ought to be there by now. should 和ought to的区别 含义大致相同， ought to 强调在客观上（法律，章程和道义），比should语气强。 should强调主观上，表示主语的职责和义务或说话人的劝告。 You ought to go and see Mary tomorrow. You shouldn't judge a man always by the clothes.

need和dare 用作情态动词时，主要用在否定句、疑问句中，用作实义动词时, 可用于各种句式。 Need I come? Yes , you must./No,you needn’t. You needn't telephone him now. She dare not go out alone at night. We should dare to give our own opinion. We need to tell them the news. 注意：dare用作实义动词时，其否定句中的to可保留也可省略。 She doesn't dare to climb the tree. She doesn't dare climb the tree.

二、情态动词的完成式和进行式 modal verb+ have done: modal verb+be doing: 对过去发生的事情进行评价、猜测，表示“应当已经、想必已经、本 来可以做但未做” I should have finished the work earlier. He isn't here. He must have missed the train. Where can (could) he have gone? You could(might) have been more careful. You ought to have come,but why didn't you? modal verb+be doing: 对正在发生的事情进行评价、猜测，表示“想必正在、可能正在、应 当正在” It's 12 o'clock .They must be having lunch. They may be discussing the problem. He can't be telling the truth. She shouldn't be working like that.She is still so weak.

情态动词专项练习 — I hear you've got a set of Australian coins. — I have a look? — Yes, certainly. A. Do B. May C.Shall D. Should 2. He seldom listens to others. He answer for what he has done. A. shall B. will C. can D. would 3. — May I leave the office before 5 o'clock in the afternoon? — No, I'm afraid you . A. needn't B. shouldn't C. mustn't D. won't 4. — Shall I tell John about it? — No, you . I don't know his telephone number. A. needn't B. wouldn't C. mustn't D. shouldn't 5. Mr Bush is on time for everything. How it be that he was late for the opening ceremony? A. can B. should C. may D. must B A C A A

6. The traffic light is red, so I stop my car. A. must B. have to C. can D. mustn't 7. — What happened to the young trees we planted? — The trees well, but I didn't water them. A. might grow B. needn't have grown C. would grow D. would have grown 8. I was really anxious about you. You home without a word. A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave 9. Tom show his exam results to his parents. A. dare not B. dared C. dare to D. dares not to 10. She the film. She knows nothing about it. A. can't see B. can't have seen C. must see D. mustn't have seen B D B A B

11. They must have been here the day before yesterday, ? A. mustn't they B. didn't they C. mustn't have they D. had they 12. — I didn't see her yesterday. — Oh, but you . A. must have B. ought to C. should have D. cannot have 13. — Must I take a bus ? — No, you . You can walk from here. A. must not B. don't C. don't have to D. had better not to 14. — Will you stay for lunch? — Sorry, . My brother is coming to see me. A. I mustn't B. I can't C. I needn't D. I won't 15. I often go fishing when I lived in the countryside. A. should B. would C. could D. might 16. — Could I use your telephone? — Yes, of course you . A. could B. will C. can D. might B C C B B C

17. — I can't get through to the general manager's office anyhow. — The line is busy. Someone the telephone. A. must use B. uses C. must have been using D. must be using 18. — Do you think he will do me a favor? — As far as I know, he is the last one to help others.He___be prepared to give you a hand, though. A. might B. must C. can D. should 19. Even though I'd hurt my leg, I swim back to the river bank. A. could B. might C. had to D. was able to 20. You go to the party if you don't finish your homework first. A. won't B. don't C. oughtn't D. shan't 21. — It is rather cold here. Shall we light a fire? —No, we because things are easy to catch fire. A. won't B. can't C. mustn't D. needn't 22. Very loud noise make people ill or drive them mad. A. should B. can C. need D. must D A D D C B