Unit 2 Grammar.ppt

1、Unit 2 Healthy eating Grammar,情态动词,情态动词,表示推测,不表示推测,can could may might shall should must will would,ought to have to need (neednt) dare (darent) used to,表示推测情态动词的重要用法,肯定的推测 可能的推测 否定的推测 疑问的推测,must,对将来 对现在 对过去,情态动词,may, might,cant, couldnt,can, could,+ V. + V. + have done 常见must be + be doing,+ V. + V

2、. + have done + be doing,+V. + V. + have done + be doing,+ V. + V. + have done + be doing,e.g. Young people should learn how to use computers. Every citizen ought to obey law. You ought not to go.,should常表示劝告、建议、命令，与ought to意义相近，但ought to多表示责任、义务，语气强烈。在疑问句中通常用should代替ought to。,must & have to,must &

3、haveto,must用于一般问句中,肯定回答用must否定式用neednt或dont have to，做“不必”,mustnt表示“禁止，不允许”,e.g. MustIfinishallassignmentsatatime?,Yes, you must. No,youneednt.,Youmustntgetoffwhilethecarisstill moving.,must +have done 表示对过去已经发生的行为进行推测，意为“想必/准是/一定作了某事”。,1.It must have rained last night, for the road was very muddy. 昨

4、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。,1. Can they have won the basketball match? 他们可能赢了篮球赛吗？ 2. It couldnt have been Mr. Green. He has gone to New

5、 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“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。,may/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

6、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“本来可能”，但实际上没有发生的事。另外，还可表示“本来应该或可以做某事”之意，含有轻微的责备语气。,1.You might not have told her. 你本可以不告诉他的。（事实上你告诉他了） 2. You might have come earlie

7、r. 你本可以早点来的。（但没有这样）,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 miss C. must have missed D. might miss,C,2. Oh, Im not fe

8、eling well in the stomach. I _ so much fried chicken just now. shouldnt eat B. shouldnt have eaten C. mustnt eat D. mustnt have eaten,B,3. -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 left C. cant come D. wont be comin

9、g 4. -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,B,D,5.-Why hasnt Jane arrived yet? -She _ again in the morning? A. shouldnt have overslept B. may have turned off the ala

10、rm clock C. must have no one t o call her D. should have someone to wake her up 6.-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 gone,B,A,情态动词考题:,1. -Did the train arrive in time? -No. It _ two hours ago

11、. A. must have arrived B. ought to have arrived C. must arrive D. ought to arrive 2. Must I drive to his house and pick up the children? No, . A. you shouldntB. you might not C. you neednt D. you mustnt,B,C,3. 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 write,C,4. There is someone knocking at the door. it be Tom? A. can B. must C. should D. ought to 5.