情态动词+have-done表推测.pptxVIP

“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 can’t 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/can’t）常译为“准是…，一定是…”如： Li Hua was so wet, 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? Can’t 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mustn’t,应根据句子的时间状语，分别采用didn’t或 haven’t(hasn’t)等。如： She must have told you about it yesterday, didn’t she? He must have lived here for a long time, hasn’t he? 4）needn’t + 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 needn’t have hurried. You needn’t 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。”如： You should/ought to have come earlier. 你应该早点儿来。 You shouldn’t/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 already. A. shouldnt have told B. may have told C. neednt have told D. couldnt have told 2) --- 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 be him. He ________ within such a short time. He said he would call me a