高考英语情态动词和虚拟语气讲解.doc

Four short words sum up what has lifted most successful individuals above the crowd: a little bit more.-author-date高考英语情态动词和虚拟语气讲解嘉兴英语教学网（一） 虚拟语气常考点（一） 虚拟语气在非真实条件句中的运用虚拟条件句主句例句与现在事实相反的假设If + 主语 + 动词的过去式（be动词were）主语 + should/ would/ could/ might + 动词原形If I had time，I would attend the meeting。If I were you，I should seize the chance to go abroad。与过去事实相反的假设If + 主语 + had + 过去分词主语 + should/ would/ could/ might + have + 过去分词If you had taken my advice，you would not have failed in the exams。与将来事实相反的假设if + 主语 + 动词过去式if + 主语 + were to + 动词原形if + 主语 + should + 动词原形主语 + should/ would/ could/ might + 动词原形If you came tomorrow，we would have the meeting。If it were to rain tomorrow，the sports meeting would be put off。If he should not come tomorrow，we should put off the meeting till next Monday。使用虚拟条件句时要注意的几点：1. 当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为“错综时间条件句”，动词的形式要根据它所表示的时间做出相应的调整。如：If you had studied hard before，you would be a college student now。假如你以前学习努力的话，你现在将已是一名大学生了。2. if省略句在条件句中可省略if，把were，had，should提到句首，变为倒装句式。如：If I were at school again，I would study harder。Were I at school again，I would study harder。假如我再次回到学校，我一定更加努力的学习。If you had come earlier，you would catch the bus。Had you come earlier，you would catch the bus。假如你来早点，你就赶上公交车了。If it should rain tomorrow，we would not go climbing。Should it rain tomorrow，we would not go climbing。假如明天下雨，我们就不去爬山了。注意：当省略的条件句中的谓语动词是否定形式时，不能用动词的缩略形式。比如，我们可以说：Were it not for the expense，I would go abroad now。但不能说：Werent it for the expense，I would go abroad now。3. 用介词短语代替条件状语从句。常用的介词有with，without，but for。如：What would you do with a million dollars？（=if you had a million dollars）假如你有一百万美元的话，你会做什么？We couldnt have finished the work ahead of time without your help。（=if we hadnt got your help）Without your help，we couldnt have finished the work ahead of time。（=But for your help， =If it had not been for your help， =Had it not been for your help，）假如没有你的帮助，我们不可能提前完成工作。4. 含蓄条件句有时为了表达的需要，在虚拟语气中并不总是出现if引导的条件句，而是通过其他手段来代替条件句。如：I was ill that day。Otherwise，I would have taken part in the sports meet。（副词）那天我病了，不然，我就去参加运动会了。He telephoned to inform me of your birthday，or I would have known nothing about it。（连词）他打电话通知了我你的生日，否则，我什么都不知道。A man who stopped drinking water would be dead in about seven days。（定语从句）一个停止喝水的人，大约会在7天以内死亡。Everything taken into consideration，they would have raised their output quickly。（独立主格结构）如果每件事情都被考虑了的话，他们已经迅速提高产量了。5. even if，even though也可用于虚拟语气，其形式与if从句在虚拟语气中的形式相同。（二） 虚拟语气在名词性从句中的运用1. 用于宾语从句中（1） wish后面的宾语从句一般用虚拟语气，表示一种不可能实现的愿望。其谓语动词构成形式为：如：I wish（that）I were a bird and could fly freely in the sky。I wish（that）I had met that film star yesterday。How I wish she could come to the party next Monday。（2） 用于表示建议、愿望、命令等词后的宾语从句中，常见的动词有：demand，order，require，insist，suggest，propose，advice等。宾语从句中的虚拟语气结构为“should + 动词原形”，should 可以省略。如：He suggested that we（should）start off early the next day。The doctor ordered that the patient（should）be sent to hospital without delay。（3） 在would rather后的宾语从句中，也用虚拟语气，其谓语动词用过去式。如：I would rather they didnt hear of the news。（4） 当suggest表示“暗示，表明”之意，insist表示“坚持认为、坚持说”之意时，suggest/ insist后的宾语从句动词已经不再后于suggest/ insist所表达的动作，这种情况下，suggest/ insist后的宾语从句谓语动词不使用虚拟语气形式，应使用陈述语气形式。如：The smile on his face suggested that he was satisfied with our work。他脸上的笑容表明他对我们的工作很满意。The man insisted that he had never stolen the money。那个人坚持说他没有偷钱。2. 用于主语从句中It is desired/ suggested/ proposed/ necessary/ important/ strange/ natural/ a pity/ essential + that从句，从句中的谓语动词用“should + 动词原形”，should可以省略。如：It is suggested that the meeting should be put off till next week。It is strange that he should have acted toward his parents like that。（act这一动作发生在主句谓语动词is之前，所以要用should have + 过去分词）注意：以上句式也可以用于陈述语气。如：Its strange that he didnt come yesterday。Its a pity that you cant dance。3. 用于表语从句和同位语从句中在suggestion，proposal，order，plan，idea，request，advice等名词后的表语从句和同位语从句中要用虚拟语气，其构成是“should + 动词原形”。如：My idea is that we should think it over before accepting it。We all agreed to his suggestion that we should go to Dalian for sightseeing。（三） as if（as though）用在虚拟语气中如果as if引导的从句谓语动词与主句谓语动词所表达的动作同时发生，as if引导的从句谓语动词用过去式；如果as if引导的从句谓语动词所表达的动作先于主句谓语动词所表达的动作，as if引导的从句谓语动词用过去完成式；如果as if引导的从句谓语动词所表达的动作后于主句谓语动词所表达的动作，as if引导的从句谓语动词用过去将来式。如：He looks as if he were an artist。（同时）She speak English so fluently as if she had studied English in America。（先于）He learns English so hard as if he would go to the U.S.A.。（后于）（四） 虚拟语气用于定语从句中It is（high）time（that）句型中，定语从句的谓语动词用过去式，或should + 动词原形（其中should不能省略）。此句型意为“（现在）该”，用来表示提议。如：It is（high）time that you went to school。It is（high）time that we should start out。易错知识总结（一） 虚拟语气的使用1. 虚拟语气表示一种不能实现的假设该语法主要用于if条件状语从句，也可用于主语从句、表语从句、宾语从句等。2. if条件状语从句中虚拟语气的判断判断是真实条件句还是非真实条件句。只有在非真实条件句中才使用虚拟语气。通过句子意思，看假设的条件是否能够实现。能够实现的是真实条件句，不能使用虚拟语气；不能实现的是非真实条件句，要用虚拟语气。判断这个假设是与哪个事实相反，通常有三种情况：（1）与过去事实相反；（2）与现在事实相反；（3）与将来事实可能相反。3. “后退一步法”后退一步法是指在准确的判断了该句与哪一事实相反后，按虚拟语气的后退一步法处理从句谓语动词的时态。即：在非真实条件状语从句中，谓语动词按正常情况“后退一步”，也就是：（1） 与过去事实相反，在从句中用过去完成时形式表示。（2） 与现在事实相反，在从句中用一般过去时形式表示。（3） 与将来事实可能相反，在从句中用一般过去将来时形式表示。主句中则用情态动词would，should，could等加一个与从句一致的动词形式。如：If I had come here yesterday，I would have seen him。如果我昨天来这儿，就会见到他了。If I were a teacher，I would be strict with my students。如果我是老师，我会严格要求学生的。If it should snow tomorrow，they couldnt go out。如果明天下雪，他们不会外出。4. 注意事项（1） if条件句中如有were，should，had，可以省去if，并使用倒装语序。（2） 在现代英语中，if条件状语从句中的谓语动词如果是be，其过去形式一般用were。-