s虚拟语气

虚拟语气可以表示过去，现在和将来的情况，时态的基本特点是时态往后推移。

a. 与现在事实相反的假设

条件从句主句

一般过去时（be用were）should（would,could,might）等+动词原形

例：If they were here，they would help you. 如果他们在这儿，会帮助你的。

If I were you，I would go to look for him. 如果我是你，就会去找他。

b. 与过去事实相反的假设

条件从句主句

过去完成时should（would）等+ have+ 过去分词

例：If he had come yesterday，I should / would have told him about it.如果他昨天来的话，我会把这件事告诉他的。

c. 表示对将来不大可能发生的事情的假想

条件从句主句

一般过去时/或should +动词原形/或were to+动词原形should（would）等+动词原形例：If you succeeded，everything would be all right. 如果你将来成功了，一切都会好的。

If you should succeed，everything would be all right.

If you were to succeed，everything would be all right.

1）在主语从句中的应用形容词a

It is important, necessary, natural, imperative, strange / a pity, a shame, no wonder/ suggested, ordered, required, proposed, demanded, requested, insisted等+ that…等结构的主语从句，谓语动词用should 加动词原形，should 可省略。

2）在宾语从句中的应用动词v

在表示命令、建议、要求等一类动词后面的从句中，像order，suggest，propose，require，demand，request，insist，command，insist + （should）do等。

例：I suggest that we （should）hold a meeting next week. 我建议下周召开个会议。

He insisted that he （should ）be sent there.他要求被派到那儿去。

注：如suggest，insist不表示"建议" 或"坚持要某人做某事时"，即它们用于其本意"暗示、表明"、"坚持认为"时，宾语从句用陈述语气。

3）在表语从句，同位语从句中的应用名词n

suggestion，proposal，idea，plan，order，advice等名词后面的表语从句、同位语从句中要用虚拟语气，即（should）+动词原形。例如：

My idea is that we（should）get more people to attend the conference.

我的想法是让更多的人来参加会议。

I make a proposal that we（should）hold a meeting next week.

我提了个建议，下周我们开个会。

4）It is （high）time that 后面的从句谓语动词要用过去式或用should加动词原形，但should 不可省略。例如：

It is time that the children went to bed. 孩子们该睡觉了。

It is high time that the children should go to bed.

5）wish后面的从句，表示与事实相反的情况，或表示将来不太可能实现的愿望。Asif, as though,形式和wish相同。

现在that+主语+ 一般过去时

过去that+主语+ 过去完成时

将来that+主语+ would/could +动词原形

例如：I wish I were as tall as you.我希望和你一样高。

He wished he hadn't said that. 他希望他没讲过那样的话。

It looks as if it wouldn’t rain tomorrow. 看上去好像明天不会下雨。

6）didn't need to do表示过去不必做某事，事实上也没做。

needn't have done表示过去不必做某事，但事实上做了。例如：

John went to the station with the car to meet Mary，so she didn't need to walk back home.

约翰开车去车站接玛丽，所以她不必步行回家了。

John went to the station with the car to meet Mary，so she needn't have walked back home 约翰开车去车站接玛丽，所以她本不必步行回家了。

（Mary步行回家了，没有遇上John的车。）

例There was plenty of time. She ___.

A. mustn't have hurried

B. couldn't have hurried

C. must not hurry

D. needn't have hurried

7）虚拟条件句的从句部分含有were，should，或had时，可省略if，变成were，should，had +主语+谓语动词的形式，进行倒装。

例Were they here now，they could help us. =If they were here now，they could help us.

Had you come earlier，you would have met him. =If you had come earlier，you would have met him.你来得早一点，就碰到他了。

Should it rain，the crops would be saved. =Were it to rain，the crops would be saved.=If it rained, the crops would be saved假如下雨，庄稼就有救了。

例____ to do the work，I should do it some other day.

A. If were I

B. I were

C. Were I

D. Was I

8）主句与从句的动作发生在不同的时间，主句从句谓语动词的虚拟语气形式因时间不同而不同，这种条件句叫做混合条件句。

例If you had asked him yesterday，you would know what to do now.

如果你昨天问过他，今天就知道做什么了。（从句与过去事实相反，主句与现在事实相反。）If it had rained last night（过去），it would be very cold today （现在）。

如果昨晚下过雨，今天就会很冷了。

exercise

1）If I hadn't stood under the ladder to catch you when you fell，you ____ now. （1999.1）

A. wouldn't be smiling

B. couldn't have smiled

C. won't smile

D. didn't smile

2）____ for my illness I would have lent him a helping hand. （19995.1）

A. Not being

B. Had it not been

C. Without being

D. Not having been

3）___before we depart the day after tomorrow，we should have a wonderful dinner party. （1997.1）

A. Had they arrived

B. Would they arrive

C. Were they arriving

D. Were they to arrive 4）Jean doesn't want to work right away because she thinks that if she ____ a job she probably wouldn't be able to see her friends very often.（1996.1）

A. has to get

B. were to get

C. got

D. could have got

5）_____ right now，she would get there on Sunday.（1996.6）

A. Would she leave

B. If she leaves

C. Were she to leave

D. If she had left

6）Had he worked harder，he ____ the exams.（1997.6）

A. must have got through

B. would have got through

C. would get through

D. could get through 7）If the whole operation _____ beforehand，a great deal of time and money would have been lost. （1999.6）

A. was not planned

B. has not been planned

C. had not been planned

D. were not planned

8）Some women ____a good salary in a job instead of staying home，but they decided not to work for the sake of the family.（2000.1）

A. must make

B. should have made

C. would make

D. could have made

9）We didn't know his telephone number，otherwise we ___ him.（1995.6）

A. would have telephoned

B. must have telephoned

C. would telephone

D. had telephoned 10）Wouldn't you rather your child _____ to bed early？（2000.1）

A.go

B.went

C.would go

D.goes

11）Mike's uncle insists ____ in this hotel.（2000.1）

A.staying not

B.not to stay

C.that he would not stay

D.that he not stay

12）Sometimes I wish I ____ in a different time and a different place.（2000.1）

A.be living

B.were living

C.would live

D.would have lived

13）It is essential that these application forms ____ back as early as possible.（2000.1）

A.must be sent

B.will be sent

C.are sent

D.be sent

14）It is recommended that the project _____ until all the preparations have been made. （1995.6）

A.is not started

B.will not be started

C.not be started

D.is not to be started

15）We are all for your proposal that the discussion ____.（1998.6）

A.be put off

B.was put off

C.should put off

D.is to be out off

16）The suggestion that the mayor ________the prizes was accepted by everyone.（2000.6）A.would present B.present C.presents D.ought to present

17）It's already 5 o'clock now.Don't you think it is about time ____？（1996.6）

A.we are going home

B.we go home

C.we went home

D.we can go home 18）As Commander-in-Chief of the armed forces，I have directed that all measures ____ for our defence.（1999.6）

A.had been taken

B.would be taken

C.be taken

D.to be taken

19）It is vital that enough money __________to fund the project. （1997.1）

A.be collected

B.must be collected

C.is collected

D.can be collected