Grammar

1. Grammar Modal verbs 情态动词

2. Must 的用法 1. 表主观义务和必要，意为“必须……一定……得……” （多用于肯定、疑问句） Eg: We must get there before five o’clock. You don’t look well, you must go and see the doctor. 2.由must引起的疑问句，肯定回答用must/have to, 否定回答用needn’t或don’t have to, 意思是“不必” Eg:  -- Must we clean all the rooms? -- Yes, we must. / No, we needn’t. ＋ ＋

3. Must I stay here after school? Yes, you must/have to No, you needn’t / don’t have to. mustn’t 表示强烈禁止，意为“不能，不准, 禁止”。 3. must表示推测，意为：一定，肯定，必然…… (只用于肯定句) must be 对现在事情的肯定推测 must be doing 对现在正在发生的事情的肯定推测 must have done 对过去事情的肯定推测

4. The school gate must be closed, for it’s already twelve o’clock. 他肯定正在阅览室读报纸。 He must be reading newspapers in the reading room now. It must have rained last night, for the ground is so wet. 你肯定看过这部电影，因为你很了解它。 You must have seen the film, for you know so much about it.

5. 5. have to表示客观的必须，意为：不得不；必须 Eg: Now there’s no bus here, so we had to walk home. We have no food home, you have to go and get some, Tom. 疑问式: (两种) Do you have to leave so soon? （用助动词） Have you to leave so soon? I don’t have to go to work today. (不需要) I haven’t to go to work today.

6. Practice 1. Mike, you ______ play with fire. You______ burn yourself. A. won’t; can’t B. mustn’t; may C. don’t have to; must D. have got to; shouldn’t B

7. 2. You ______ see the doctor, Joe. You don’t look very well. A. must B. shall C. may D. can A 3. — Must I clean the window now? — No, you ______. A. mustn’t B. needn’t C. can’t D. may not B

8. 4. Jack’s ill, so they ______ change their plans. A. must B. should C. have got to D. ought to C 5. Harry has been reading all day —he ______ be tired. A. should B. has got to C. has to D. must D

9. 情态动词：had better, should, ought to 用于表达给别人建议或陈诉自己的观点。 • had better do… “最好做……” • had better not do… “最好不……” • Eg: You had better go to hospital at once. • We’d better not eat so much junk food. • 2) 疑问句 had better 通常用于否定疑问句中 • Hadn’t＋主语＋better do…？表劝告 • Eg: 你是不是最好帮一下他？ • Hadn’t you better help him? • 你是不是最好今晚呆在家里？ • Hadn’t you better stay at home tonight? ＋ ＋

10. should/ought to do… 应该做…… shouldn’t /ought not to do … 不应该做… Eg: You should/ought to work harder . You don’t look well. You ought to/should go to see a doctor. You oughtn’t to smoke so much! 2) 疑问句 Should＋主语＋do…？/Ought ＋主语＋to do…? Eg:  Should you do that? Ought you to smoke so much? 明天我们要去学校吗？ Ought we to go to school tomorrow? ＋ ＋

11. should/ought to 与完成式连用, 表遗憾或责备 should＋have done/ought to have done 意为“本应该做……但实际上并没有做” shouldn’t ＋have done/ oughtn’t to have done 意为“本不应该做……但实际上已经做” Eg: You should/ought to have told me the news yesterday . you shouldn’t have quarreled with him. Jacky Cheung’s concert was so wonderful! You should have come with us last night. ＋ ＋

12. Should与ought to 的不同 should 可用来表示意外、惊喜、不可思议。译为“竟会”、“居然”。 Eg: Such a well-behaved gentleman should be so rude to a lady! Tom should have past the maths test! 2) should be可用来表示有较大可能实现的猜测、推论, 常译为“可能……”、“应该会(不会）…” Eg:  They should be home by now, I think. 你准备这么充分，通过考试应该没有什么困难。 You are well prepared. There shouldn’t be difficult for you to pass the exam? ＋ ＋

13. 1. ---- Write to me when you get home. ---- ______. A. I must B. I should C. I will D. I can 2. ---- Will you stay for lunch? ---- Sorry, ______. My brother is coming. A. I mustn’t B. I can’t C. I needn’t D. I won’t C B

14. 3. ---- Did you scold him for his carelessness? • ---- Yes, but ______. • I’d rather not to • B. I’d rather not have done • C. I shouldn’t do • D. I’d better not do B

15. 4. You didn’t go to the party yesterday, or I ______ you. A. would see B. could see C. might have seen D. might see 5. Look what you have done. You ______ have been careful. A.should B. can C. must D. may C A

16. 6. The cat ______ hibernate(冬眠) in winter. A. don’t need B. doesn’t need to C. needs not to D. needs not B

17. 4. 表示否定推测用can’t can’t be “肯定不是，不可能是” Can’t have done… “不可能做过某事” Eg: The man can’t be our manager, for he has gone to London for business. The book can’t be mine, for I’ve lent my book to John. 昨天你不可能见过Tom, 因为他已经回美国了。 You can’t have seen Tom yesterday, for he has gone back to the US.