英语中的虚拟语气

如题所述

虚拟语气用来表示说话人的主观愿望或假想,而不表示客观存在的事实,所说的是一个条件,不一定是事实,或与事实相反。虚拟语气通过谓语动词的特殊形式来表示。英语中的语气分为陈述语气、祈使语气、虚拟语气三类。
条件状语从句
条件状语从句分类
  条件句可分为两类,一类为真实条件句,一类为非真实条件句。非真实条件句表示的是假设或实际可能性不大的情况,故采用虚拟语气。
用法及动词形式
  1、表示与现在事实相反的情况:   从句:If 主语+过去时(Be动词用were)   主句:主语+should/would/could/might+do
2、表示与过去事实相反的情况   从句:If 主语+had+done   主句:主语+should/would/could/might+have done 
3、表示对将来情况的主观推测   从句:①if+主语+were to do 主句:①主语+should/would/could/might+do   ②if+主语+did/were ②主语+should/would/could/might+do    ③if+主语+should+do ③主语+should/would/could/might+do 
4、 有时,虚拟条件句中,结果主句和条件从句的谓语动作若不是同时发生时,虚拟语气的形式应作相应的调整。这种条件句叫错综条件句。   ①从句的动作与过去事实相反,而主句的动作与现在或现在正在发生的事实不符。
②从句的动作与现在事实相反,而主句的动作与过去事实不符。
5、 当虚拟条件句的谓语动词含有were,should,had时,if可以省略,这时条件从句要用倒装语序,即把were,should,had等词置于句首,这种多用于书面语。
 6、非真实条件句中的条件从句有时不表达出来,只暗含在副词、介词短语、上下文或其他方式表示出来,这种句子叫做含蓄条件句,在多数情况下,条件会暗含在短语中,如without…,but for…等
7、 有时,虚拟条件句中,主、从句可以省略其中的一个,来表示说话人的一种强烈的感情。
8.注意,在虚拟语气的从句中,动词be的过去时态一律用were,不用was。
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第1个回答  2012-05-10
1.虚拟语气在条件句中的用法
        (1)若表示与现在事实相反的假设,则条件从句中用过去式,主句中用过去将来式(would,should,could,might + 动词原形);若表示某事将来实现的可能性不大,则条件从句中用should + 动词原形也可用“were to+动词原形”或用过去式动词。如:
            I would certainly go if I had time.(现在)
            If it should rain,we wouldn”t go out.(将来)
            If I knew German,I would read the paper to you.(现在)
            If he were here,we could ask him.(现在)
        (2)若表示与过去事实相反的假设,从句中用过去完成式,主句中用过去将来完成式(should,would,could,might + have + 过去分词)。如:
            If I had set off a little earlier, I would have caught the train.
            She would / might have come if she hadn”t been so busy.
            If I hadn”t taken your advice,I would have made a bad mistake.
            If only you hadn”t told him the news.
        (3)含有虚拟语气的条件状语从句中,如有had,should,were 这三个词的话,在正式或书面语言中可将if省略,再将句子的主语和谓语动词实行全部倒装或部分倒装。如:
            Had they time(=If they had time),they would certainly come and help us.
            Should it be fine(=If it should be fine),we would go for an outing.
            Were I go(=If I were you), I would go.
        (4)若主句从句所指的时间不一致,即条件从句表示与过去事实相反,主句表示与现在事实相反;或者条件从句表示与现在事实相反,主句表真实情况,则从句中应采用与具体时间相对应的虚拟形式。如:
            If it had rained last night(过去),It would be very cold today(现在).
            If I had taken your advice(过去),I should have no trouble with the work now(现在).

2.虚拟语气在宾语从句中的用法
        在动词suggest,order,demand,propose,request,command,insist等后的宾语从句中,用虚拟语气(即Should+动词原形或只用动词原形)来表示愿望、建议、命令、请求等。在动词wish /would rather后的宾语从句中,用过去式表示与现在事实不符,用过去完成式表示与过去事实不符。如:
            I suggest that we(should)set off at once.
            The doctor insisted that the patient (should)be X-rayed.
            I wish I were as strong as you.
            I would rather that you hadn”t told him.

3.虚拟语气在主语从句中的用法
        在It is necessary/important/strange/natural;It is requested/suggested/desired/proposed;it is a pity等结构后的主语从句中要用虚拟语气,即Should+动词原形或只用动词原形。如:
            It is necessary that he(should)be sent there at once.
            It is requested that Professor Li(should)give us a speech.
            It is desired that we(should)get everything ready by tonight.

4.虚拟语气在表语从句、同位语从句中的用法。
        在 suggestion, proposal,idea,plan,order,advice等名词后的表语从句、同位语从句中要用虚拟语气,即should+动词原形或只用动词原形。如:
            Our suggestion is that you( should)be the first to go.
            My advice is that we(should)send for Doctor Li.
            Do you know the order that you(should)keep watch?

5.虚拟语气在其他状语从句中的用法
        在as if引导的状语从句中,用过去式表示与现在事实不符,用过去完成式表示与过去事实不符;在so that,in order that引导的状语从句中,常用should/would/could/might+动词原形来表示虚拟语气。如:
            They talked as if they had been friends for years.
            She stayed at home for a few days so that she could take care of her mother.
            He took a taxi to the station so that she should not miss the train.

6.虚拟语气在定语从句中的用法:
        在it is time后面的定语从句中常用过去式表示虚拟。