【3年高考2年模拟】2016届高三英语一轮复习课件语法专练七情态动词和虚拟语气_高考复习指南

【3年高考2年模拟】2016届高三英语一轮复习课件语法专练七情态动词和虚拟语气

　　must have done

　　想必/准是/一定做了否定式为:can’t/couldn‘t+have done It must have rained last night,for the road is quite muddy. 昨晚一定下雨了,因为路很泥泞。

　　can/could have done

　　1.本来能够做 2.过去可能会做 Can he have gone to his aunt’s? 他有可能去他姨妈家了吗? cannot/could not have done 1.过去不可能 2.过去没能够 He cannot have forgotten it. 他不可能忘了那件事。 may/might have done 也许/或许已经做……,一般只用于肯定句或否定句中(在否定句中表示“可能不”),不用于疑问句中。用might则表示语气更加不肯定。 It’s too late.I think he may have gone to bed. 太晚了,我想他或许已经睡了。 He may not have finished the work. 他也许还没完成那项工作。 should/ought to have done 本该做而实际上未做 You ought to have done this exercise more carefully. 你本应该更仔细地做这个练习。 should not/ought not to have done 本不该做而做了 You shouldn’t have told her the truth.你本不该告诉她真相。 needn’t have done 本不必做而做了 You needn’t have taken a taxi here,for it was very near to my house.你本来不必打车来这里的,因为离我家很近。 had better have done 当时最好做了(其否定式 had better not have done表达相反的含义) You had better not have scolded her. 要是那时你没责骂她就好了。 would rather have done 宁愿当时做了(其否定式would rather not have done表达相反含义,两者都有“后悔”之意) I raised objections at the meeting,but now I would rather not have done that.我在会上提出了反对意见,但现在我宁愿没那么做。 would like/love to have done sth. 过去愿意做但未做成 I would love to have gone to the party last night,but I had to work extra hours to finish a report. 昨晚我本来很想去参加聚会的,但我得加班完成一个报告。七、情态动词的其他用法要点: 1.cannot but+do sth.表示“不得不,只好做某事”。如: I cannot but choose to go.我只好去。 2.may well和may as well结构。 “may well+动词原形”是一种常用结构,意为“完全能,很可能”,相当于 be very likely to+动词原形。如: He may well be proud of his son. 他大可为他的儿子感到自豪。 Her appearance has changed so much that you may well not recognize her. 她的模样变化太大,你很可能认不出她了。 “may as well+动词原形”意为“最好,不妨,倒不如”。如: You may as well do it at once.你最好马上就做这件事。 We may as well stay where we are. 我们留在现在的地方倒也不错。 3.cannot(或can never)与enough连用表示“再……也不为过”。(具体用法见形容词和副词专题。) 4.may可以用于祈使句,表示祝愿。如: May we never forget each other.愿我们彼此永不相忘。 May you return in safety.愿你平安归来。 5.“Why/How+should”结构表示说话人对某事不能理解,感到意外、惊讶等意思,意为“竟会”。如: Why should you be so late today?你今天怎么来得这么晚? How should I know?我怎么会知道?(意为:我不知道。) 6.must表示“偏要,硬要”。如: Must you make so much noise? 你非得弄出这么大声响吗? 7.may作“可以”讲时,其否定式常用“mustn’t”表示“禁止”;must作 “必须”讲时,其否定式是“needn’t”,表示“不必”。如: —May I use your car? —No,you mustn’t. ——我能用用你的车吗? ——不,一定不能。 (委婉的拒绝可用:Sorry,but I am using it now.或You’d better not.等) —Must I work out the problem tonight? —No,you needn’t. ——我今晚必须做出这道题吗? ——不,不必。 8.need和dare的用法 need和dare两者既可用作情态动词也可用作行为动词。作行为动词时,有人称和数的变化,可用于肯定句、否定句或疑问句中,构成否定句或疑问句时要用助动词do,does,did;作情态动词时,没有人称和数的变化(dare的过去式dared),直接接动词原形,多用于否定句和疑问句中,构成否定句和疑问句时不用助动词。另外,dare作情态动词时,还可用于条件句中,过去式为dared;作行为动词时, dare用于疑问句或否定句,后面的to也可省略;I dare say是习惯说法,意为 “我想,大概”。如: He needn’t do it.(情态动词) He doesn’t need to do it.(行为动词) 他不必做这件事。 I didn’t know whether he dared say that to him.(情态动词,有时态变化) 我不知道他是否敢对他说那话。 He didn’t dare(to)do it.(行为动词) He dared not do it.(情态动词) 他不敢那么做。注意:need作行为动词时,还可表示“需要”,物作主语时,后接动名词的主动形式表示被动含义(详见非谓语动词专题)。如: The floor needs sweeping.这地需要打扫了。