unit2-healthy-eating--grammar情态动词

1、Grammar情态动词表示推测表示推测情态动词的重要用法情态动词的重要用法肯定的推测肯定的推测可能的推测可能的推测否定的推测否定的推测疑问的推测疑问的推测must 对将来对将来 对现在对现在 对过去对过去情态动词情态动词may, might cant, couldntcan, could + V. + V. + have done常见常见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与与ought to 的区别的区别should常表示劝告、建议、命令，与常表示劝告、建议、命令，与ought to意意义相近，但义相近，但ought to多表示责任、义务，语气强多表示责任、义务，语气强烈。在疑问句中通常用烈。在疑问句中通常用should代替代替ought to。 must & have tomust have to主观客观 主观 客

3、观时态 现在，将来 多种表推测询问意愿否定意禁止，不允许 不必must & have tomust用于一般问句中用于一般问句中,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，不允许许” e.g.MustIfinishallassignmentsatatime?Yes,youmust.No,youneednt.Youmustntgetoffwhilethecarisstillmoving.must +have done 表示对过去已经发生的事情进行肯定推测，意为“想必/准是/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， 因为地上很泥泞。2.We must have learned 2,000 words by the end of last term. 到上学期为止我们一定学了有两千个单词 。3.He must have gone to Beijing. 他一定已经去北京了。 can/could+have done表示对过去的行为的怀疑和不肯定，通常用在否定句和疑问句中。Where can Mary have put the empty bottles?玛丽可能

5、会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，他已经去北京了。could(不用can)+have done,在肯定句中表示“g过去本来能够而没能”，具有婉转的批评和责备之意。1. I could have passed my exam easily, but I made too many stupid mistakes. 我本来能够轻易通过考试，但我犯了太多不该 犯的错误。2.You could have reported to me earlier. 你本该早点告诉我的。m

6、ay/might+have done表示对过去已发生行为的推测，意为“也许/或许已经”。一般只用于肯定句和否定句中，不用于疑问句。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，我想他可能已经睡觉了。2. He may/might not have finished the work.他可能没有完成工作。might（不用may）+have done表示“过去本来可能发生的事，但实际上没有发生的事。含有轻微的责备语气。1. You might have come earlier.你本可以早点来的。

7、（但没有这样）2.You might not have told her.你本可以不告诉他的。（事实上你告诉他了）neednt +have done表示做了本来不必去做的事。1.She neednt have gone to the station yesterday.昨天她本不必到火车站去的.（昨天她去了）2.You neednt have bought it.你本可不必买它的。 （你买了）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情态动词考题情态动词考题: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