unit2-healthy-eating--grammar情態(tài)動詞

1、Grammar情態(tài)動詞表示推測表示推測情態(tài)動詞的重要用法情態(tài)動詞的重要用法肯定的推測肯定的推測可能的推測可能的推測否定的推測否定的推測疑問的推測疑問的推測must 對將來對將來 對現(xiàn)在對現(xiàn)在 對過去對過去情態(tài)動詞情態(tài)動詞may, might cant, couldntcan, could + V. + V. + have done常見常見must be + be doing + V. + V. + have done + be doing 可以用可以用not表示表示“可能不可能不” +V. + V. + have done + be doing+ V. + V. + have done + b

2、e doing e.g. Young people should learn how to use computers. Every citizen ought to obey law. You ought not to go.Should與與ought to 的區(qū)別的區(qū)別should常表示勸告、建議、命令，與常表示勸告、建議、命令，與ought to意意義相近，但義相近，但ought to多表示責(zé)任、義務(wù)，語氣強多表示責(zé)任、義務(wù)，語氣強烈。在疑問句中通常用烈。在疑問句中通常用should代替代替ought to。 must & have tomust have to主觀客觀 主觀 客

3、觀時態(tài) 現(xiàn)在，將來 多種表推測詢問意愿否定意禁止，不允許 不必must & have tomust用于一般問句中用于一般問句中,肯定回答用肯定回答用must否否定式用定式用 neednt或或dont have to，做做 “不必不必”,mustnt表示表示“禁止，不允禁止，不允許許” e.g.MustIfinishallassignmentsatatime?Yes,youmust.No,youneednt.Youmustntgetoffwhilethecarisstillmoving.must +have done 表示對過去已經(jīng)發(fā)生的事情進行肯定推測，意為“想必/準(zhǔn)是/一定作了某事”

4、。1.It must have rained last night, for the road was very muddy. 昨晚 一定是下雨了， 因為地上很泥濘。2.We must have learned 2,000 words by the end of last term. 到上學(xué)期為止我們一定學(xué)了有兩千個單詞 。3.He must have gone to Beijing. 他一定已經(jīng)去北京了。 can/could+have done表示對過去的行為的懷疑和不肯定，通常用在否定句和疑問句中。Where can Mary have put the empty bottles?瑪麗可能

5、會把空杯子放在哪里呢？2. It couldnt have been Mr. Green. He has gone to New York. 那不可能是格林先生的，他已經(jīng)去北京了。could(不用can)+have done,在肯定句中表示“g過去本來能夠而沒能”，具有婉轉(zhuǎn)的批評和責(zé)備之意。1. I could have passed my exam easily, but I made too many stupid mistakes. 我本來能夠輕易通過考試，但我犯了太多不該 犯的錯誤。2.You could have reported to me earlier. 你本該早點告訴我的。m

6、ay/might+have done表示對過去已發(fā)生行為的推測，意為“也許/或許已經(jīng)”。一般只用于肯定句和否定句中，不用于疑問句。might比may更委婉、含蓄和不肯定。 1. Its too late. I think he may have gone to bed.太晚了，我想他可能已經(jīng)睡覺了。2. He may/might not have finished the work.他可能沒有完成工作。might（不用may）+have done表示“過去本來可能發(fā)生的事，但實際上沒有發(fā)生的事。含有輕微的責(zé)備語氣。1. You might have come earlier.你本可以早點來的。

7、（但沒有這樣）2.You might not have told her.你本可以不告訴他的。（事實上你告訴他了）neednt +have done表示做了本來不必去做的事。1.She neednt have gone to the station yesterday.昨天她本不必到火車站去的.（昨天她去了）2.You neednt have bought it.你本可不必買它的。 （你買了）1. -I wonder why they are late? -They _ the train. cant have missed B. could missC. must have missed D

8、. might missC2. Oh, Im not feeling well in the stomach. I _ so much fried chicken just now. A. shouldnt eat B. shouldnt have eaten A.C. mustnt eat D. mustnt have eatenB5. -Has Mike started? He said he would join in the party. -He _. He is a man of keeping his word.A. could have left B. must have lef

9、tC. cant come D. wont be coming6. -There were already five people in the car, but they managed to take me as well. -It _ a comfortable journey.A.cant be B. mustnt have been C. should be D. couldnt have been BD 7.-Why hasnt Jane arrived yet? -She _ again in the morning?A. shouldnt have overslept B. m

10、ay have turned off the alarm clockC. must have no one t o call herD. should have someone to wake her up8.-Did you go to the movie the day before yesterday? -No. We _, but we decided not to.A.should have gone B. could go C. should go D. could have goneBA情態(tài)動詞考題情態(tài)動詞考題:1. -Did the train arrive in time?-

11、No. It _ two hours ago.A. must have arrived B. ought to have arrivedC. must arrive D. ought to arrive2. Must I drive to his house and pick up the children? No, . A. you shouldnt B. you might not C. you neednt D. you mustntB C 3. We didnt see Tom at the meeting yesterday. He it. A. mustnt have attend

12、ed B. cannot have attended C. neednt have attended D. would have not attendedB 4. You _ such a long composition. The teacher only asked for 300 words. You have written 600. A. mustnt have written B. couldnt have written C. neednt have written D. do not have to writeC 5. There is someone knocking at the door. it be Tom? A. can B. must C. should D. o