第六节 情态动词
【名师导读】
第一步学习目标：掌握情态动词后面必须跟动词原形，没有人称和数的变化的特点。理解常见情态动词的基本用法。
情态动词是用来表示说话人的语气和态度，如请求、命令、劝告、建议、禁止、猜测、义务等。它们本身有一定的词义，但在句中不能单独作谓语，后面必须跟一个动词原形才能作谓语，没有人称和数的变化，部分情态动词有时态的变化。情态动词像助动词一样，能帮助主要动词构成否定形式和疑问形式。
【考点一】 can, may, must, have to
口诀 情态动词这一伙，表示语气和情态， 人称与数无变化，动词原形跟着它。 疑问形式它提前，否定它not加. can用来表能力，还表请求和允许， 礼貌请求用could, 回答它时要用can. may 意思表“可以”，否定回答用can’t(或mustn’t). must“必须”或“义务”，否定mustn’t表禁止。 否定回答needn’t ，must be 推测表“一定”。 have to 与must意相近，两者可以互换用， have to 客观must主观，人称时态数变化。 should肯定表“应该”，同义句型ought to. will, would 表示“愿意”，否定形式是won’t (或wouldn’t). |
【说明】
（1）can表示能力，意为“能，会”之意，其过去时为could表示“过去能”。另外，can还可以表示请求和允许，意为“可以”，这时候与may意思一样，可以互换。如果要表示更礼貌的的请求，通常用could来表示，这时候它的回答应用can来回答。
（2）may一般表示许可，意为“可以，允许”之意，may引导的一般疑问句的否定回答通常用can’t或mustn’t来回答。
（3）must作“必须”“应该”解，表示必要性；mustn’t则表示“不应该，不许，禁止”之意。回答Must …?引出的问句时，肯定回答用must, 否定回答用needn’t或don’t have to. 另外，“must have +过去分词”表示“想必”之意，是对过去事情的推测。
（4）have to 与must含义相近，两者往往可以互换使用，但have to强调客观上需要做的事情，而must则强调主观上需要做的事情。have to有人称、时态和数的变化，而must没有变化。have to变为否定句和疑问句时要通过助动词do, does, did来变化。
（5）should表示“应该”之意，否定形式为shouldn’t，表示“不应该”，should的同义词为ought to和be supposed to.
【典型例题】
(1) --Can you dance? --Yes, I can. /No, I can’t.
(2) That can’t be Li Hong. He has gone to Hainan. 那不可能是李红，他去海南了。
(3) The book must belong to Lucy. 这书肯定是露西的。
(4) --May I borrow your pen, please? 我可以借你的钢笔吗？
--Yes, you may. /No, you can’t/mustn’t. 可以。/不可以。
(5) --I can’t find my pen.我找不到我的钢笔。
--It may be in your pencil-box. 可能在你的文具盒里。
(6) --Must I finish my homework now? 我必须现在完成作业吗？
--Yes, you must. / No, you needn’t/don’t have to. 是的。/不必。
【考点二】 need用法巧学巧记
need的用法口诀 实义动词表“需要”，后跟名、代、不定式。 need后跟动名词，主动形式被动意。 情态动词表“需要”，没有时态人称数。 其后直接跟动原，常用疑问、否定句。 |
【说明】
（1）need to do sth. (主语是人，表主动含义)
need doing sth.（主语是物，表被动含义）
（2）need作为情态动词用时，只用于疑问句和否定句，后面直接跟动词原形，这时没有人称、时态和数的变化。
（3）Need I …?的肯定回答为：Yes, you must. 否定回答为：No, you needn’t.
【典型例题】
(1) They need to climb up the trees with ladders. 他们需用梯子爬那些树。
They don’t need to climb up the trees with ladders. 他们不需用梯子爬那些树。
They needn’t climb up the trees with ladders.
(2) The bike needs repairing.
=The bike needs to be repaired.
自行车需要修了。
【考点三】 had better的用法
had better的用法口诀 表达“建议”和“忠告”，had better是“最好”。 建议某人“最好不”， 后跟动原来记住. had提前疑问句, had better not 否定句。 |
【说明】
had better (not) do sth. 最好（不要）做某事
【典型例题】
(1) You’d better not swim in the river. It’s very dangerous.你最好不要在河里游泳，很危险。
(2) Today is very hot. You’d better take off your coat. 今天很热，你最好脱下你的外衣。
【考点四】 used to的用法
used to的用法口诀 used to用法要注意，后跟动原要牢记。 表示“过去常做事”，现在已经不做了。 疑问句首加Did, 也可把used放在前。 否定形式didn’t use to, used变usedn’t也可。 还有一点要注意，be/get used to 后跟V-ing. |
【说明】
（1）used to表示“过去常常做某事”，后跟动词原形，没有人称的变化。
（2）used to 的疑问式有两种：在句首加Did，然后把used还原成use；也可以直接把used提前即可。
（3）used to的否定式也有两种：把used to变为didn’t use to或usedn’t to即可。
（4）be/get used to 表示“习惯做某事”，后跟名词或V-ing形式。
【典型例题】
(1) used to 的肯定、否定和疑问式
肯定式：He used to get up early.
否定式：He didn’t use to get up early. / He usedn’t to get up early.
疑问式：Did he use to get up early?
Yes, he did./No, he didn’t.
或：Used he to get up early?
Yes, he used (to). /No, he usedn’t (to).
(2) He used to get up early, but now he is used to getting up late. 他过去常常早起，但现在习惯晚起。
(3) Jim used to be short, but now he is tall. 吉姆过去矮，但现在高了。
【考点五】must, may/might, can’t表示“猜测”时的区别
must: 表示“肯定”的猜测。
may/might: 表示“可能”，不一定。
can’t: 表示“不可能”。
【典型例题】
1. --The person must be Jim. He always wears a white T-shirt.
--It can’t be him. He has gone to London.
2. --What would you send to your sister as her birthday present?
--I haven’t decided yet. I may send her a skirt.
【基础巩固 课堂练习】
第二步学习目标：能用所学基本知识解决以下问题。
I. 用can, can’t, may, must, mustn’t, needn’t, couldn’t填空。
1. --_____ we finish the exercises today?
--No, you ______. You ___ finish them tomorrow.
2. The little girl _____ draw at the age of four, but now she ____ draw very well.
3. –How about seeing a film tonight?
--I’m afraid I _____. I ____ finish my homework first.
4. I’m sure you can pass the exam. You ____ worry.
5. --_____ I ask you some questions?
--Of course, you ______.
6. --____ I leave now?
--No, you ____. You ____ leave when I come back.
II．选择题。
( ) 7. You ____ be tired after playing sports for a long time without a rest.
A. must B. need C. can’t D. needn’t
( ) 8. –What are you going to do this Saturday?
--I’m not sure. I ____ go shopping.
A. must B. may C. can D. can’t
( ) 9. –Look at the boy on the playground. It ____ be Sam.
--No, it ____ be him. He has gone to England.
A. must, can’t B. may, can
C. must, mustn’t D. can’t, can’t
( ) 10. –What will the weather be like tomorrow?
--It ___ be rainy, cloudy or sunny. Who knows?
A. must B. might C. shall D. should
( ) 11. –Could I go to the movie, Mum?
--Of course you ____. But you ____ come back before ten o’clock.
A. could, must B. can, must
C. could, may D. can, can
( ) 12. --____ I use your ruler, please?
--Sure. Here you are.
A. May B. Would C. Need D. Must
( ) 13. We ____ stop our cars when the traffic light turns red.
A. may B. can C. could D. must
( ) 14. –Who is the girl over there?
--Well, if you ____ know, her name is Sally.
A. must B. may C. can D. shall
( ) 15. –Must we water the flowers today?
--No, you _____. You can do it tomorrow.
A. mustn’t B. can’t C. need D. don’t have to
( ) 16. –Can your friend play the violin?
--Yes, she ______. But she can’t play it well.
A. must B. can C. could D. should
( ) 17. You have already tried your best, so you _____ worry about the matter.
A. needn’t B. mustn’t C. couldn’t D. can’t
( ) 18. –I can’t stop playing computer games.
--For your health, I’m afraid you ____.
A. can B. may C. have to D. must
( ) 19. Yesterday it rained heavily when school was over. We _____ stay in our classroom.
A. should B. must C. had to D. could
( ) 20. –You must come to the meeting on time.
-- I _____.
A. must B. have to C. will D. should
( ) 21. –May I go surfing alone this afternoon?
--No, you _____. It’s too dangerous.
A. may not B. needn’t C. don’t D. can’t
( ) 22. –What are you going to have for supper?
--I _____ have dumplings.
A. must B. need C. can D. may
( ) 23. --_____ we go now, Mike?
--Sure. Let’s go.
A. Will B. Shall C. May D. Must
( ) 24. You _____ to school tomorrow if you go to hospital.
A. don’t need come B. won’t need come
C. needn’t to come D. don’t need to come
( ) 25. It ____ be very difficult to learn English well, isn’t it?
A. must B. should C. need D. has to
( ) 26. He ____ be a teacher, but now he is a doctor.
A. used to B. use to
C. was used to D. is used to
( ) 27. Tom, you _____ play with the knife, you ____ hurt yourself.
A. won’t; can’t B. mustn’t; may
C. shouldn’t; must D. can’t; shouldn’t
( ) 28. It’s raining hard. You _____ go out.
A. had better not B. had better not to
C. hadn’t better D. had better to not
( ) 29. You ____ go and ask Lily, she ____ know the answer.
A. must; can B. must; may
C. need; can D. can; may
( ) 30. Let’s move the bags away, or there ____ an accident.
A. maybe B. may have C. may be D. will have
( ) 31. This kind of car ___ run very fast. It’s new.
A. can B. is able to C. could D. has to
( ) 32. –Need I go home now? --______.
A. Yes, you need B. Yes, you must
C. No, you mustn’t D. No, you may not.
( ) 33. –Miss Wang, we must hand in our homework today, needn’t we ?
--No, you _____. But you must bring it to school tomorrow.
A. mustn’t B. shouldn’t C. can’t D. needn’t
III．句型转换。
34. You’d better go out with an umbrella. (改否定句)
You ____ ____ ____ go out with an umbrella.
35. He used to play basketball. (改一般疑问句并回答)
____ he _____ ____ play basketball?
Yes, he _____. /No, he ______.
36. We have to put off the sports meeting because of the heavy rain. (改否定句)
We ______ _____ to put off the sports meeting because of the heavy rain.
37. He could swim when he was ten. (同义句)
He ____ ____ _____ swim ____ ____ ____ ____ ten.
38. You should pass something to old people with your both hands. (同义句)
You _____ ______ _____ pass something to old people with your both hands.
39. You mustn’t talk loudly in the library. (祈使句)
_______ _______ loudly in the library.
40. I can tell you something about the art of dressing. (一般疑问句)
_____ ______ tell me _____ about the art of dressing?
【质量标准控制 考试满分过关】
以上40小题中，做错的题目有：
____________________________________；
解决日期是：________________________；
解决途径：__________________________；
感谢恩人：__________________________.
【全面冥想 纵横联系 睡前练习 终生记忆】
第三步学习目标：重点知识再现，加深印象
1. 闭上眼睛，花2分钟回忆常见的情态动词有哪些？它们有什么特点？如何变为否定句和一般疑问句？
2．回忆need, had better, used to的用法，must, may, can’t的区别。
【链接中考 轻松备考】
第四步学习目标：能用所学知识解决2011年中考题。
( ) 1. -- Can you ride a horse?
-- No. I _ ___ . 【2011北京】
A. needn't B. may not C. can't D. mustn't
( ) 2. You _____ lose your way if you walk alone in the mountains at night. 【2011上海】
A. may B. need C. should D. ought to
( ) 3.--______ I borrow your history book?
--Sure. Here you are. 【2011江苏淮安】
A. Must B. May C. Need D. Will
( ) 4. --Could I use your eraser for a while? --Yes, of course you _____.【2011宁夏】
A. could B. can C. will D. Should
( ) 5.--Can I skate on the lake now?
-- No, you ____. It’s dangerous. 【2011山东】
A. can’t B. mustn’t C. needn’t D. won’t
( ) 6. --Whose notebook is this?
--It _____ be Ning’s. It has her name on it.【2011湖南张家界】
A. can B. must C. might
( ) 7. --Must I finish my math exercises after scool?
--No, you ____. 【2011湖南益阳】
A. mustn’t B. don’t have to C. can’t
( ) 8. --Be quiet, Mr. Smith is coming.
--Don’t worry. It ____ be him. Mr. Smith is much taller. 【2011四川广元】
A. mustn’t B. must C. can’t
( ) 9. It rained heavily, so we ____ stay at home watching TV or surfing the Internet all day. 【2011四川乐山】
A. could B. had to C. must
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