情态动词

1. Modal verbs 情态动词

2. 情态动词表示说话人对动作或状态的各种观点和态度，如需要、猜测、意愿或怀疑等。情态动词有词义，但不完全，是所谓的“辅助性”动词，在句中不能单独充当谓语。情态动词表示说话人对动作或状态的各种观点和态度，如需要、猜测、意愿或怀疑等。情态动词有词义，但不完全，是所谓的“辅助性”动词，在句中不能单独充当谓语。

3. 一、表示许可 may, might, can, could 在口语中可用can，could代替may，但在正式场合用may。表示允许时，也可用might代替，might不表示过去时，而是表示口气比较婉转。May/Can/Could/Might I have a talk with you?　　我可以和你谈谈吗？－Could I use your dictionary? 我可以用一下你的字典吗？－Yes, go ahead.可以，用吧。 (或Yes, you can.但不能说Yes, you could.) ☆ May I ...? 问句常见的肯定回答和否定回答：肯定回答 否定回答 Certainly. No, you mustn't.(具有强烈禁止的意思) Yes, please. No, you can't.(最常见) Yes, of course. Please don't./You'd better not. Sure. I don't think you can. Go ahead, please. I'm sorry it's not allowed.

4. 二、表请求 may, might, will, would －May/Might I come into the room to see my mother?　　我可以进房间看我母亲吗？－No, you mustn't. She needs to have a good rest.　　不，你不能进。她需要好好休息。 will和would可用于第二人称疑问句，表示请求和建议等。would比will委婉客气。Will you share your happiness with us?　　你可以把你的欢乐与我们共享吗？☆Will/Would you ...? 表示请求和建议的答复：肯定回答 否定回答 Yes, please. 是的，请。 I'm sorry. I can't. 对不起，不行。 Certainly. 当然可以。 No, thank you. 不，谢谢。 Sure. 当然了。 No, I won't. 不，不行。 All right. 好啊！

5. 三、表能力 can, could 表示能力，可译为“能，会”。The cinema can seat 1,000 people. 这电影院能容纳1000人。I could not read such an easy book when I was 7 years old.　　我七岁时连如此简单的书也看不懂。☆can与be able to的区别①can表示“能力”时，和be able to相当，许多场合都可以互相替换。但当叙述过去经过一番努力才能完成的事情或前面有特殊说明，表示你有能力时，只能用be able to。【误】The fire spread the building quickly but everybody could escape.【正】The fire spread the building quickly but everybody was able to escape.②be able to比can有更多形式。When he grows up, he will be able to support his family.③could经常和动词see, hear, smell, taste, feel, remember, understand等连用。 When we went into the house, we could smell something burning.④在谈论说话时发生的动作，用can，不用be able to。【误】Look! I'mable to swim.【正】Look! I can swim.

6. 四、表示习惯 will, would, used to will和would可表示某种倾向或习惯性动作。will表示现在的习惯动作，would表示过去的习惯动作。used to表示过去的习惯或过去某时期的状况，但现在已不存在。 He will surf the Internet every night. He would be nervous when he met strangers. He used to drink tea but now he drinks coffee.He is not what he used to be.☆would和used to的用法比较。①used to表示过去与现在或过去某时与后来的情况有不同，强调“现已无此习惯了”，而would只表示过去的情况，与现在无关。②used to可表示过去的习惯动作或状态，而would只表示过去的习惯动作。 ③used to可泛指过去的习惯性动作或状态，而would表示过去的习惯性动作时，往往要带有一个特定的时间状语。 【误】We would play hide-and-seek in the fields.【正】We used to play hide-and-seek in the fields.【正】Whenever we were in the country, we would play hide-and-seek in the fields.

7. 五、表示意愿 will, would, shall ☆ will和would可表示意志、愿望和决心，用于各种人称陈述句。I will do anything for you.None is so blind as those who won‘t see.They would not let him in because he was poorly dressed. ☆ shall表示说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、三人称陈述句中。You shall do as I say.　　按我说的做。(命令)Nothing shall stop us from carrying out the plan.什么也阻止不了我们执行这项计划。(决心)He shall have the book when I finish reading.我看完这本书就给他看。(允诺) You shall fall behind in your exam if you keep playing.如果你一直玩，你就会在考试中落后。(警告)

8. 六、表义务 must, have to, should, ought to 1.must表示有做某一动作的必要或义务，强调主观看法，可译为“必须，应该”。Everyone must obey the rule.Teachers must be patient enough with their students. 2.have to表示因客观需要促使主语不得不做某事。 You can't turn right here. You have to turn left. 3.must与have to的比较。 ①must含有说话者的强烈决心(表示主观的看法)，have to则表示外力环境或习惯使然(即表示客观的必要，作“不得不”解)。I must study hard. 我必须努力学习。 (发自内心的决定)I have to study hard.我不得不努力学习。　(外界因素逼迫) ②must只有一种形式，而have to可有多种时态。They had to put off the sports meet due to the bad weather.③must的否定式和have to的否定式的意思完全不同。You must keep it a secret. Youmustn't tellanyone.Youdon't have to tellme the secret. (mustn‘t表示“禁止”) (don't have to意思是"没有必要"= don't need to)

9. 4.Should 表示义务，意为"应该"(某件事宜于做)，用于各种人称。One shouldn't be selfish.Children should obey their parents. 5.Ought to表示义务，意为“应该”(因责任、义务而该做)，口气比should稍重。 We ought to defend our country.6.ought to与should的比较。ought to和should的含义较近，但不完全相同。ought to表示“应该”，是从“义务”或“按理推断”的角度来讲的。Should则是从说话人的个人看法这一角度来讲的。You are her mother. You ought to look after her.(是道义上的责任，不能和should互换。) Children should be seen, not heard.对孩子要观其行，不要听其言。 提　示　表示“义务”时，我们在口语中可以用be supposed to来代替should和ought to。I'm supposed to be there at 8:00.　我应该八点到那里。

10. 七、表猜测 must, may, might, can, could, should, ought to 1. 适用范围和可能性的大小 must表示推测时，它的肯定程度比may，might，could大得多，一般只用于肯定句。 may, might表示推测，一般只用于肯定句。可译为“可能，也许”。(一般情况下，might表示的可能性很小)can和could表示推测，可用于肯定句(can罕见)、否定句和疑问句，但更常见于疑问句或否定句。在此种用法中can和could没有时态的区别，只是表示可能性的大小，can表示推测的可能性比could大。 should表示对过去、现在或将来情况的某种推测，可译为“可能、照说应该”。 一般用于肯定句，可指人的直觉或个人看法。 It should be fine tomorrow. ought to表示推测，暗含很大的可能，可译为“应该是，会是”。 一般用于肯定句，可指人的直觉或个人看法。 Prices ought to come down soon.

11. 2. 猜测用法中时态的表示 情态动词 + do (这里的do通常是状态动词或系动词)，表示对现在状态的推测。 Carolmust getvery bored with her job. She does the same thing every day.He's just had his lunch. He can't behungry. 情态动词 +be doing表示对现在动作或状态的推测。 Put on more clothes. You must be feeling cold with only a shirt on.情态动词 +have done表示对过去的动作或状态的推测。 Leslie walked past me without speaking. He can‘t/couldn’t have seen me.

12. 情态动词在虚拟语气中的用法 1. “should ／ ought to＋完成式” 表示 “本应当做某事，而实际上并没有做”； “shouldn’t ／ oughtn’t to＋完成式”表示 “本来不应当做，而实际上却做了”。2. “may／might＋ 完成式” 表示 “本来可以干某事却没有干”，突出其可能性；而 “could＋ 完成式” 表示“本来能够做某事，但实际上却没有做”。3. “needn’t ＋完成式” 表示 “本来没必要做某事，实际上却做了

13. 八、部分情态动词的固定搭配 Can和 could 的一些固定搭配 1.Can’t/couldn’t help doing 忍不住；不禁、、、 He can’t help laughing. 2.Can’t/couldn’t but + 动词原形 只好、、、；不得不、、、 I couldn’t but admit that he was right and I was wrong. 我不得不承认他对了，我错了。 3.cannot/couldn’t … too + 副词/形容词; cannot/couldn’t …+副词/形容词 + enough 无论、、、也不过分； 越、、、越好 You can’t be too careful when crossing the street. I cannot thank you enough. 我对你感激不尽。

14. may 和might 的某些固定搭配 • may well + 动词原形 理应、、、；有足够的理由、、、 • We may well say she is a good teacher. • 我们大可说她是一位优秀的老师。 • 2. may/might as well + 动词原形 不妨、、、；还不如、、、 • You never listen---- I might as well talk to a brick wall. • 你从来不听我的话，我还不如对着一堵墙说话。 • 3. may…but 或许会、、、但是、、、 • She may be beautiful, but she is cool. • 她也许算的上美丽，但太冷漠了。 • 英语口语中dare的几个常用结构： • ○I dare say...我想，大概，可能，或许…… • I dare say things will improve. 我想情况会好转的。 • ○How dare you ...? 你怎么敢……？ • How dare you ask me such a question? 你怎么敢问我这样的问题？ • ○I dare you ... 我谅你也不敢…… • I dare you to tell your parents! 我谅你也不敢告诉你父母！

15. 九、“情态动词 + have done”是情态动词的一个十分重要的结构，这种结构有两个主要的用法。 ☆表示对过去发生动作或状态的推测或估计 may / might have done 表示“大概已经” 通常用于肯定句和否定句。might有时可用于疑问句。 can / could have done 表示“可能已经” 通常用于疑问句和否定句。could有时可用于肯定句。 must have done 表示“一定已经” 只用于肯定句，具有较大的可能性。 should have done 表示“应该” 可能性较小。

16. ☆表示对过去发生动作的遗憾或责备 might have done 表示“本可以” 通常用于肯定句。 could have done 表示“本可以” 通常用于肯定句。 should have done 表示“本应该” 可用于肯定句、否定句和疑问句。（否定表示本不该） ought to have done 表示“本应该” 同should have done。 needn't have done 表示“本没有必要” 只用于否定句。

17. 否定的情态动词的用法: mustn’t 不准, 禁止 needn’t 没必要 ( = don’t have to ) can’t 不能; 不可能 may not 不可以; 可能不 shouldn’t 不应该 ( = ought not to ) shan’t 禁止 daren’t 不敢

18. Have a try!

19. Translation • 1. 那小女孩没有出门。她现在一定在做家庭作业。 • 2. 路上是湿的。昨晚一定下雨了。 • 3. 我刚刚拜访过他。他现在一定呆在家里。 • 4. — 你为什么没有接电话？ • — 我当时一定是在睡觉所以没听见。 • 5. 那男孩想必已经完成了他的家庭作业了。

20. 1. The girl is not out. She must be doing her homework now. 2. The road is wet. It must have rained last night. 3. I have just dropped in on him. He must stay at home. 4. —Why didn’t you answer my phone call? —Well, I must be sleeping, so I didn’t hear it. 5. The boy must have finished his homework.

21. —How’s your tour around the North Lake? Is it beautiful? • —It ________ be, but it is now heavily polluted. • A. will B. would C. should D. must • 2. —Guess what! I have got A for my term paper. • —Great! You ______ read widely and put a lot of work into it. • must B. should • C. must have D. should have

22. 3. The teacher _______ have thought Johnson was worth it or she wouldn‘t have wasted time on him, I suppose. A. should B. can C. would D. must 4. In crowded places like airports and railway stations, you___ take care of your luggage. A. can B. may C. must D. will 5. My MP4 player isn’t in my bag. Where ____ I have put it? A. can B. must C. should D. would

23. 6. The biggest problem for most plants, which ________ just get up and run away when threatened, is that animals like to eat them. A. shan’t B. can’t C. needn’t D. mustn’t 7. —She looks very happy. She ______ have passed the exam. —I guess so. It’s not difficult after all. A. should B. could C. must D. might 8. —Where is my dictionary? I remember I put it here yesterday. —You ___it in the wrong place. A. must put B. should have put C. might put D. might have put

24. 9. As a result of the serious flood, two-thirds of the buildings in the area . A. need repairing B. needs to repair C. needs repairing D. need to repair 10. I told your friend how to get to the hotel, but perhaps I have driven her there. A. could B. must C. night D. should

25. 11. — I think I’ll give Bob a ring. — You _______. You haven’t been in touch with him for ages. A. will  B. may  C. have to  D. should12. Some aspects of a pilot’s job _____ be boring, and pilots often _____work at inconvenient hours. A. can; have to  B. may; can       C. have to; may     D. ought to; must

26. 13. We  ____  have proved great adventurers, but we have done the greatest march ever made in the past ten years. A. needn’t   B. may not   C. shouldn’t   D. mustn’t14. —Is Jack on duty today?  —It ____ be him. It’s his turn tomorrow.  A. mustn’t  B. won’t  C. can’t  D. needn’t15. If it were not for the fact that she _______ sing, I would invite her to the party. A. couldn’t      B. shouldn’t      C. can’t      D. might not

27. 16. As you worked late yesterday, you ______ have come this morning. A. needn’t    B. mayn’t    C. can’t     D. mustn’t17. There‘s no light on — they______ be at home. A. can’t     B. mustn’t         C. needn’t         D. shouldn’t

28. 18. —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 19. —May I pick a flower in the garden? — ________. A. No, you needn’t B. Not, please. C. No, you mustn’t D. No, you won’t

29. 19. Put on more clothes. You be feeling cold with only a shirt on.  A. can  B. could  C. must  D. would 20. "Must I drive to his house and pick up the children?"   "No, ."  A. you shouldn't  B. you might not   C. you needn't   D. you mustn't

30. 21. There is someone knocking at the door. it be Tom?A. Can  B. Must  C. Should  D. Ought to 22. Two year 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 not   C. should not   D. don't have to

31. 23. —Excuse me, but I want to use your computer to type a report. —You ___ have my computer if you don’t take care of it. A. shan’t B. might not C. needn’t D. shouldn’t 24. Everything has two sides. Beautiful songs, sometimes, _____ be just noisy to others . A. must B. may C. should D. could. 25. —May I speak to the patient now? —No, you _____. He is too weak now. A. needn’t B. may not C. mustn’t D. oughtn’t

32. BYE BYE -_____-|||