情态动词 II.pptVIP

Grammar 情态动词 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. 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 。 2. 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 couldn’t 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“本来能够…而没能…”，具有婉转的批评和责备之意。 You could have told me earlier. 你本该早点告诉我的。 should/ ought to + have done用于肯定句时，表示“本该做某事而实际上没做”，用于否定句时，则表示“不该做的事反而做了”。 You should have told him a week ago. 你本来应该在一周前告诉他的。 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 earlier. 你本可以早点来的。（但没有这样） needn’t + have done表示做了本来不必去做的事。 1. She needn’t 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 needn’t have bought it. 你本可不必买它的。 （你买了） 巩 固 练 习 1. Oh, I’m not feeling well in the stomach. I ____ so much fried chicken just now. A. shouldn’t eat B. shouldn’t have eaten C. mustn’t eat D. mustn’t have eaten 2. --- Why hasn’t Jane arrived yet? --- She ____ again in the morning? A. shouldn’t have overslept B. may have turned off the alarm clock C. must have no one t o call her D. should have someone to wake her up 3. --- 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 1．The flower is dead. I _______ it yesterday. A．should water B．must water C．should have watered D．mustn’t have watered 2．What time ought I _______? A．arrived B．arriving C．arrive D．to arrive 3．He _______ speak to his mother like that. A．ought not to B．doesn’t ought to C．not ought t