Modal Verbs

1. Modal Verbs possibility:can / could, may / might certainty:must, will, should ability:can / could, be able to permission:can / could, may / might requests:can / could, will / would

2. suggestions:could / may /might, shall necessity:must, have to, have got to, need advice:ought to, had better

3. 用法辨析 1. can和be able to 1) can (could) 表示能力、可能, 只用于现在式和过去式 2) be able to可以用于各种时态。

4. 只用be able to的情况： a. 位于助动词后。 b. 情态动词后。 c. 表示过去某时刻动作时。 e. 表示成功地做了某事或表在某种特定条件下的“能够”

5. 3. have to和must 1) 两词都是“必须”的意思, have to 表示客观的需要, must 表示说话人主观上的看法, 即主观上的必要。 e.g. My brother was very ill, so I had to call the doctor in the middle of the night. He said that they must work hard. 2) have to有人称,数,时态的变化,而must只有一种形式。 e.g. He had to look after his sister yesterday. 3) 在否定结构中：don’t have to 表示“不必”; mustn’t表示”禁止”。 e.g. You don’t have to tell him about it. You mustn’t tell him about it.

6. 4. will和would 常见用法 1) would like to do = want to 想要 e.g. Would you like to go with me? 2) Will you…? / Would you like…? 表示肯定含义的请求劝说时,疑问句中一般用some, 而不是any。 e.g. Would you like some cake? 3) won’t you是一种委婉语气。 e.g. Won't you sit down?

7. will 和 would考察难点 • will 除了表将来以外，还可表“意愿，期望”和表习惯性，倾向性，经常性的“必然，总是”,如用于过去式，则改成would • e.g. I have made up my mind to go and I will. • He will sit there for hours reading. • If you keep on doing like that, the accidents will happen. • I told him not to go but he wouldn’t listen to me. • 2. will （表示功能）能；行 • e.g. This will do if there is nothing better. • The door won’t open. • 3. would (表过去习惯性动作）老是，总会 • e.g. On Sundays he would come to see his aging parents. • As a child, my father would have a swim in the river after school during summer.

8. 5. Shall 和should 常见用法 • Shall＝will用于第一人称表将来 • Shall 用于问句中，一三人称，征求对方意见 e.g. Shall we go out for a meal tonight? • should （表示义务；责任；劝告；建议时）应当；应该 e.g. Young people should learn how to respect the elder.

9. shall 和should考察难点 • shall 用于陈述句二三人称中，表示“允诺，告诫，警告，威胁，命令，决心，预言等” e.g. They shall pay what they have done. （威胁） If you work well, you shall have higher wages.（允诺） If he does’t give me what I want, I shall kill him. （恐吓） You shall do as I order. （命令） • should （表示可能性；推测；推论或期待）该；可能 e.g It’s 4:30. They should be in New York by now. — When can I come for the photos? I need them tomorrow afternoon. — They ___ be ready by 12:00. A. can B. should C. might D. need 3. 虚拟语气中的should，should 可省略(I drop cards)

10. 情态动词表推测

11. must表示推测 must用在肯定句中表示较有把握的推测, 而且一般上下句中有客观依据。意为“一定”。 e.g. 1. You have worked hard all day. You must be tired.（对现在情况的推测判断) 2. Look, the light in his office is still on. He must be working. 比较: He must be staying there.他现在肯定呆在那里。 He must stay there. 他必须呆在那。 e.g I didn’t hear the phone. I must have been asleep.must 表示对已发生的事情的推测时, 要接完成时。

12. can表推测 推测的否定形式, 用can’t, couldn’t表示。意为“不可能”。 can 也可用于疑问形式。 e.g. It can’t be him. He has gone to Shanghai. Mike can’t have found his car, for he came to work by bus this morning. Look, someone is coming. Who can it be? 注: ①could推测时不表示时态,其推测的程度不如can。有时可用于肯定句，相当于may/ might e.g. I don’t know his age. He could be thirty or thirty-five。 ②can表推测一般不用于肯定句中，但 偶尔也会在肯定句出现can. e.g. Anybody can make mistakes

13. may /might 表推测 may/might表推测时，可能性较弱，多为主观推测，没有事实依据。might比may语气更弱。 e.g. ① It may rain tonight. ② -- I didn’t see Mary at the meeting yesterday. --- She might have been ill, I guess

14. 难点：情态动词+have done 表示对已发生动作的推测，后悔等 • must, can/could, may/might 表推测时的完成式 • should have done 本应该做某事,而事实上并没有做 ought to have done shouldn’t have done 本不应该做,而事实上却做了 ought not to have done • could have done 本能够做，但却没有做 • needn’t have done 本没必要这样做，但做了 • would like/love to have done 本打算／想做，但没做

15. e.g. 1. You ought to / should have been more careful in this experiment. 2. He ought not to / shouldn’t have thrown the old clothes away. 3. -- You took a taxi? The store is only 5 min’s walk from your house? -- I could have walked there. But My leg got hurt yesterday. 4. I dressed very warmly for the trip, but I needn’t have done so. The weather was hot. 5. I would like to have read the article, but I was very busy then.

16. 其他情态动词 had better表示“最好” had better (not) do sth e.g. It is pretty cold. You’d better put on my coat. She’d better not play with the dog. You had better have come earlier.(表示与事实相反的结果,意为“本来最好”) would rather表示“宁愿” would rather (not) do would rather…than…宁愿…而不愿 would sooner\ had rather\ had sooner 表示"宁愿"、"宁可"的意思。 e.g. If I have a choice, I had sooner not continue my studies at this school.

17. need和dare 这两词既可做实义动词用,又可做情态动词用。但两者作情态动词时一般不用于肯定句而作实义动词可用于肯定，否定，疑问。 e.g. He doesn’t dare to cross the river. You need not see him.

18. used to do 可把used to看作实义动词，也可看作情态动词。 e.g. He used to work hard, didn’t he? / usedn’t he?

19. B 3. — The room is so dirty. ___we clean it? — Of course. A. Will B. Shall C. Would D. Do 4. （2003春招）My English-Chinese dictionary has disappeared. Who ___ have taken it? A. should B. must C. could D. would 5.— Is John coming by train? — He should, but he ____ not. （2002） He likes driving his car. A. must B. can C. need D. may 6. — I heard they went skiing in the mountains last winter. — It __ true because there was little snow there. (2002 北京) A. may not be B. won’t be C. couldn’t be D. mustn’t be C D C

20. D 7.（2002上海)It has been announced that candidates __ remain in their seats until all the paper have been collected. A. can B. will C. may D. shall 8. —I hear you’ve got a set of valuable Australian coins. ___ I have a look? （2002春招） —Yes, certainly. A. Do B. May C. Shall D. Should 9. （2002上海春招）Oh, I’m feeling well in the stomach, I ___ so much fried chicken just now. A. shouldn’t eat B. mustn’t have eaten C. shouldn’t have eaten D. mustn’t eat B C

21. B 10. （2001全国）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 11. （2001上海）You can’t imagine that a well-behaved gentlemen ___ be so rude to a lady. A. might B. need C. should D. would 12.—Write to me when you get home. — ____. （2001春招） A. I must B. I should C. I will D. I can C C

22. A 13. (2001上海春招) 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 14.—Are you coming to Jeff’s party? — I’m not sure. I ___ go to the concert instead. (2000) A. must B. would C. should D. might 15. (2000上海春招) My sister met him at the Grand Theatre yesterday afternoon, so he __ your lecture. A. couldn’t have attended B. needn’t have attended C. mustn’t have attended D. shouldn’t have attended D A

23. A 16.（2000春招） Sorry, I’m late. I ___ have turned off the alarm clock and gone back to sleep again. A. might B. should C. can D. will 17. （1999上海）There was a lot of fun at yesterday’s party. You ___ come, but why didn’t you? A. must have B. should C. need have D. ought to have D

24. A 18.— I stayed at a hotel while in New York. — Oh, did you? You ___with Barbara. （1998） A. could have stayed B. could stay C. would stay D. must have stayed 19. （1997）The fire spread through the hotel very quickly but everyone ___ get out. A. had to B. would C. was able to D. could 20. （1997上海）Jack ___ yet, otherwise he would have telephoned me. A. mustn’t have arrived B. shouldn’t have arrived C. can’t have arrived D. needn’t have arrived C C

25. A 21.（1996上海）When he was there, he ___ go to that coffee shop at the corner after work everyday. A. would B. should C. had better D. might 22. （1996上海）Sir, you ___ be sitting in this waiting room. It is for woman and children only. A. oughtn’t to B. can’t C. won’t D. needn’t A

26. C 24. （1995）It’s nearly seven o’clock. Jack ___ be here at any moment. A. must B. need C. should D. can 25. （1995上海）I wonder how he ___ that to the teacher. A. dare to say B. dare saying C. not dare say D. dared say D