1、,“情态动词+have+过去分词”表推测性的用法（1）“could/can+ have +过去分词”有时表示“过去可能完成（本能够做, 本可以做，本应该做）而事实上并未实现的动作”含有惋惜的感情。He cant have called on her yesterday.Where can Tom have gone?We could not have heard what he said because of the noise in the classroom.You could have done the work better.你本来可以做得更好,（2）may/might +have+过
2、分分词，表示对过去事情的推测，一般不用于疑问句，虽然may/might均指过去，但might表示推测的可能性和实际情况相反，含有“责备，抱怨”之意，译为“可能,或许，本可以已经”如：It is no use going to her office, she may have gone home.去她的办公室没有用，她也许回家了。You might have come earlier.你本来可以早一点来呀。,（3）must + have + 过去分词，表示对过去事情的较有把握的推测。一般只用于肯定句（疑问句和否定句中用can/cant）常译为“准是，一定是”如：Li Hua was so wet
3、, she must have fallen into the water.李华全身都湿了，她一定是掉进水里了。Where can Smith have put the matches? Cant he have thrown them away?史密斯把火柴放哪儿了？他不会把火柴扔了吧？含must + have +过去分词结构的句子，其反意疑问句不可以用mustnt,应根据句子的时间状语，分别采用didnt或 havent(hasnt)等。如：She must have told you about it yesterday, didnt she?He must have lived her
4、e for a long time, hasnt he?,4）neednt + have + 过去分词，表示没有必要做或不需要做某事，常用于否定句，表示过去不必做或不需要做的事情，但都已经做过了。There was plenty of time, you neednt have hurried.You neednt have gone to the station.(5)ought to/should + have + 过去分词，这种结构表示对过去事情的推测，ought to 的语气比should强。在肯定句中，表示过去“本应该做而未做的动作；”而在否定句中则表示过去“本不该发生却发生了的事情
5、。”如：You should/ought to have come earlier. 你应该早点儿来。You shouldnt/ought not to have done it yourself.你本不应该自己做那项工作的。How I regretted the days when I played and should have studied.我多么后悔那本该用来学习却玩掉了的时光。,Choose best answer for each blank.1) - I told him the news just now. - Really? You _ him. He knew it al
6、ready. A. shouldnt have told B. may have told C. neednt have told D. couldnt have told2) - I cant find my pen anywhere. I _ it. - Thats impossible. I saw you writing with it ten minutes ago. A. might lose B. would havelost C. should have lost D. must have lost,C,D,3) - That must be Jack. - It cant b
7、e him. He _ within such a short time. He said he would call me as soon as he arrived. A. mustnt have arrived B. shouldnt have arrived C. cant have arrived D. need not have arrived4) - Where are Joan and Mary? - I think they _ early. A. should have left B. must have left C. can have left D. neednt ha
8、ve left,C,B,8) - John passed the exam, although he didnt study very much for it. - The exam _ difficult. A. cant have been B. must have been C. couldnt be D. might have been9) - I wonder why they are late. - They _ the train. A. can miss B. may have missed C. could miss D. might miss 10)- He _ to he
9、lp us yesterday, but he didnt. - You must forgive him. He was ill yesterday. A. should have come B. could have come C. must have come D. can have come,A,B,A,高考链接（2010安徽）1. Jack described his father, who _a brave boy many years ago, as a strongwilled man. A. would be B. would have been C. must be D.
10、must have been 解析：句意为“杰克把他的父亲描述为一个意志坚强的人，他的父亲多年前肯定很勇敢。”用must have been表示对过去事情的肯定推测。答案：D.,（2010山东）2. I_ have watched that movie itll give me horrible dreams. A. shouldnt B. neednt C. couldnt D. mustnt解析：句意应为“我本来不应该看那部电影的-它会使我做噩梦的。”表示“本来不应该做而做了某事”用shouldnt have done, 所以A项正确。答案：A,（2010天津）3. Mark have h
11、urried. After driving at top speed, he arrived half an hour early. A. neednt B. wouldnt C. mustnt D. couldnt 句意：迈克本来不必要那么忙的。这么高速驾驶之后，他早半个小时到达了。解析：根据后面的语境，提前半个小时到达，说明Mark本来不必那么匆忙，所以用neednt have done 结构，表示“本来不必要做某事的而实际上做了”。答案：A.,(2009福建) 4. But for the help of my English teacher, I _ the first prize i
12、n the English Writing Competition. A. would not win B. would not have won C. would win D. would have won,B,(2009江苏) 5.He did not regret saying what he did but felt that he _it differently.A. could express B. would express C. could have expressed D. must have expressed,C,（2008山东） 6.Thank you for all
13、your hard work last week. I dont think we _ it without you. A. can manage B. could have managed C. could manage D. can have managed,B,2008江西）8.What a pity！ Considering his ability and experience, he _ better. A. need have done B. must have done C. can have done D. might have done,D,（2007 浙江） 9. My cats really fat. You _ have given her so much food. A. wouldnt B. couldnt C. shouldnt D. mustnt,C,（2007 江西) 10.Where is my dictionary? I remember I put it here yesterday. You _it in the wrong place. A. must put B. should have put C. might put D. might have put,D,
