虚拟语气讲解与练习

一、英语中的条件句可分为真实条件句与非真实条件句。由if引导的非真实条件句表示对现在、过去、将来的事实进行假设时，主句与从句中谓语动词的形式可分为以下三类：

二、wish后的宾语从句常使用虚拟语气。表示对现在的假设时，从句的谓语动词用一般过去式（be动词用were）。

表示对过去的假设时，从句的谓语动词为： had + 过去分词或 could/would + have + 过去分词。

表示对将来的愿望时，从句的谓语动词用would/ could/might + 动词原形。

三、在表示命令、建议或要求等动词后的宾语从句中要求用虚拟语气，谓语形式为：should+动词原形。这类动词有：ask， advise， suggest， request， commend，decide， determine， insist， intend， prefer， propose，order， recommend， imagine等。

四、lest， in case或for fear that（以防，万一，唯恐）引导的目的状语从句常用虚拟语气，谓语动词用should+动词原形。lest， for fear that从句中的should可以省去，in case从句中的should通常不省略，但是in case引导的从句也可用陈述语气。

五、在as if或as though引导的方式状语从句中，若从句的内容并非现实，则需用虚拟语气，谓语动词与if引导的非真实条件句的虚拟式一样。

六、虚拟语气用于主语从句的常见结构是It is +形容词/名词+that引导的主语从句，主语从句的谓语动词为should+动词原形。适合此结构的形容词和名词包括advisable， appropriate， desirable， essential，fundamental， imperative， important， necessary，proper， urgent， vital， a pity， s shame， no wonder that等。

七、一些表示建议、命令、要求名词后的表语从句及同位语从句中常用虚拟语气，谓语动词的形式为should+动词原形。这类名词有：suggestion， proposal，requirement， order， demand， decision， advice，desire， idea， importance， instruction， necessity， motion， preference， recommendation， resolution，request。

八、It is high/about time引导的从句中，谓语动词要用一般过去式或（should） + 动词原形表虚拟，表示（早）该做……的时候了。

九、would rather， would sooner， would just as soon， might as well， would prefer之后的宾语从句用虚拟语气表示愿望，意为宁愿、但愿，形式为：表示与现在或将来的愿望：would rather/sooner +主语+动词过去式（be动词用were）； 表示对过去的愿望：would rather/sooner+主语+had+过去分词。

十、if only引导的感叹句表示但愿，要是……就好了其用法和wish基本相同， 只是感彩更强烈。表示现在的情况，谓语动词用过去式；表示过去的情况，谓语动词用过去完成式；表示将来的情况，谓语动词用would/ could+动词原形。

十一、 should have done或ought to have done意为本应该……，表示本应该做某事，而实际没有做，含有责备或遗憾的语气。其否定形式为should not have done或ought not to have done，意为本不该做某事，表示某种行为不该发生但却发生了。

十二、may/might have done表示对过去情况的一种不太有把握的推测，表示过去可能已做了某事。其否定形式表示过去可能还没有做某事。

十三、could have done表示对过去能做而未做的事感到惋惜和遗憾。

十四、must have done用于肯定句，表示过去一定做过某事，是很有把握的推测。其否定形式为can’t / couldn’t have done。

十五、needn’t have done 表示过去没必要做某事，实际上却做了。

练习题及解析

1.Jack described his father， who _____ a brave boy many years ago， as a strong-willed man.

A.would be B. would have been

C. must be D. must have been

选D ，对过去事情的肯定推测，describe sb. as 意为把某人描绘成……

2.―The weather has been very hot and dry.

―Yes. If it had rained even a drop， things would be much better now！ And my vegetables ______.

A.wouldn’t die B. didn’t die

C. hadn’t died D. wouldn’t have died

选D，if从句用过去完成时，主句用情态动词should/would/could/might+完成时，表示与过去事实相反。

3.If he ____ my advice， he wouldn’t have lost his job.

A.followed B. should follow

C. had followed D. would follow

选C，根据wouldn’t have lost 可判断if引导的状语从句与过去事实相反。

4.George is going to talk about the geography of his country，but I’d rather he ____ more on its culture.

A.focus B. focused C. would focus D. had focus

选B，would rather后面用虚拟。表示与现在或将来事实相反，动词用过去式；与过去事实相反时，动词用过去完成时。

5.If we ____ the other road， we might have arrived here in time for the meeting.

A.take B. had taken C. took D. have taken

选B，根据might have arrived可知是与过去事实相反，故应选had+过去分词形式。

6.Sorry， Professor Smith. I didn’t finish the assignment yesterday.

Oh， you ____ have done it as yesterday was the deadline.

A.must B. mustn’t C. should D. shouldn’t

选C，此处表示和过去事实相反，should+完成时表示本来应该做而未做。

7.John went to the hospital alone. if he _____ me about it，I would have gone with him.

A.should tell B. tells C. told D. had told

选D，根据went判断，此题是与过去事实相反的虚拟语气，故从句用had+过去分词。

8.Had I known about this computer program， a huge amount of time and energy _______.

A.would have been saved B. had been saved C. will be saved D. was saved

选A，省略了if 的虚拟语气倒装句，完整的从句应为：If I had known about this computer program， 故主句应用情态动词+完成时。

9.But for the help of my English teacher， I _____ the first prize in the English Writing Competition.

A.would not win B. would not have won

C. would win D. would have won

选B，but for 引导含蓄虚拟语气，与过去事实相反，相当于if it hadn’t been for，故句子谓语动词用would/ should/could/might/+have done结构。

10.This printer is of good quality. If it ____ break down within the first year， we would repair it at our expense.

A.would B. should C. could D. might

选B，与将来事实相反的虚拟语气。if从句did/were to/should+do，主句should/would/could might +do， 此题中should表示万一。

11.He did not regret saying what he did but felt that he____ it differently.

A.could express B. would express

C.could have expressed D. must have expressed

选C，could have done意为本来能够干某事而结果没有干。

12.She _____ have left school， for her bike is still here.

A.can’t B. wouldn’t

C. shouldn’t D. needn’t

选A，can’t have done sth.，表示推测，意为不可能干某事，shouldn’t have done，本不该做实际上做了 ，needn’t have done，本没必要做而实际上已做了。

13.What a pity！ Considering his ability and experience，he ____ better.

A.need have done B. must have done

C. can have done D. might have done

选D，might have done，本来可以做某事而实际上并没有做。

14.Where is my dictionary？ I remember I put it here yesterday.

―You ___ it in the wrong place.

A.must put B. should have put

C. might put D. might have put

选D，might have put，对过去情况的推测，意为也许或有可能做过某事。

15.I’m sorry. I ____ at you the other day.

Forget it. I was a bit out of control myself.

A.shouldn’t shout B. shouldn’t have shouted

C. mustn’t shout D. mustn’t have shouted

选B，shouldn’t have done，本不应该做某事而实际上已经做了。

16. Thank you for all your hard work last week. I don’t think we ____ it without you.

A.can manage B. could have managed

B.C. could manage D. can have managed

选B，与过去事实相反，意为如果没有你的帮助，我们就不可能成功。

17. The weather turned out to be fine yesterday. I _____ the trouble to carry my umbrella with me.

A.should have taken B. could have taken

C. needn’t have taken D. mustn’t have taken

选C，needn’t have done，本不必做而做了，take the trouble to do sth.，不怕费事或困难尽力做某事。

18. I was on the highway when this car went past followed by a police car. They ____ at least 150 kilometers an hour.

A. should have been doing B. must have been doing

C. could have done D. would have done

选B，must have done 表示对过去事情的肯定推测。