虚拟语气的基本内容【开头引入】If 如果(如果有两种可能,有可能发生的，不可能发生的。
)①有可能发生If it rains tomorrow, I will not go to the park.②不可能发生虚拟语气，例如，如果我是姚明，。
虚拟语气表示说话人的愿望，假设，猜测或建议，而不表示客观存在的事实。
所以，凡表示与事实不符的假设，想象，愿望时，需用虚拟语气表达。
一、If 引导的虚拟（一）If 引导的虚拟语气,可用下表表示。
例如：①与现在事实相反：If I had wings, I would fly over the sea.②If she were rich, she would buy a bigger house.If there were no gravity, we would not be able to walk on the earth.②与过去事实相反：If You had gone to the party, You would have seen YaoMing.If you had taken my advice, you would not have failed in the exam.③与将来事实相反：If he were to tomorrow, We would have the meeting.If he should come tomorrow, We could go to the park together.If there were a heavy snow next Monday, we would not go skating.（二）if虚拟语气条件句的省略倒装。
如果虚拟条件从句中有were, had, should,可把if 省略，把were, had, should 提到主语前面，成为倒装结构。
①If I were you, I would accept the challenges.----Were I you, I would accept the challenges②If you had informed me earlier, I wouldn’t have signed the contract.----Had you informed me earlier, I wouldn’t have signed the contract.③If she should be my daughter, I wouldn’t allow her to study abroad.要不是…”①Were it not for your help, I would never be a good boss.要不是你的帮助，我永远成不了一个好的老板。
②Had it not been for you, I would have lost my way.当时要不是你，我就迷路了。
**如果谓语动词是否定形式，不能用动词的缩略形式。
3. If it weren’t for the expense, I would go broad now.Were it not for the expense, I would go abroad now.Exercises.11.Had she worked harder, she _____________________ (succeed).2.If the lawyer had been here last Saturday, he ________________me from going. (prevent)3.__________ such a disaster _________, the damage would be incalculable. (occur)4._________he _________ today, he would get there by Friday. (leave)5.If there were life on Mars, such life forms __________ unable to survive on the earth.(be)6.--Did you remind him of the meeting?--No, if I __________at home, I would have.(be)7.—John went to the hospital alone.—If he _____ me about it , I would have gone with him.A. should tellB. tellsC. toldD. had told9. If we ____ the other road, we might have arrived here in time for the meeting.A. takeB. had takenC. tookD. have taken10. This printer is of good quality. If it ____ break down within the first year, we would repairit at our expense.A. wouldB. shouldC. couldD. might11. Had I know about this computer program, a huge amount of time and money ____.A. would have been savedB. had been savedC. will be savedD. was saved二、错综时间条件句*注意：考试时会出现一种情况，从句动作发生的时间和主句动作发生的时间不一致，被称为“错综时间条件句”，我们要分别根据从句和主句的动作发生的时间对其进行虚拟。
例如：①If you had followed my advice just now, you would be better now.如果你刚才听了我的建议，你现在就好多了。
②If you had studied hard before, you would be a college student now.如果你以前好好学习的话，你现在就是大学生了。
③If he were free today, we would have sent him to Beijing.如果他今天方便的话，我们就可以把他送到北京去了。
Exercises 21.May be if I ____science, and not literature then, I would be able to give you more help.A. studiedB. would studyC. had studiedD. was studying2. Look! If we had begun to do the work yesterday morning, we ____ ourselves just like them.A. would have enjoyedB. were to enjoyC. should enjoyD. would be enjoying3. If you had taken the medicine yesterday, you ________ so bad now.A. wouldn’t have feltB. don’t feelC. wouldn’t be feelingD. aren’t feeling4. If the United States had built more homes for the poor in 1995, the housing problems now in some parts of this country __________ so serious.A. wouldn’t beB. won’t beC. will not have beenD. would not have been三、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引导的条件从句，而是通过介词短语，副词，连词替代来代替条件从句。
例如：1. 如果没有你的帮助，我们不可能提前完成任务。
If it had not been for your help, we couldn’t have finished the work ahead of time.➢Had it not been for your help, …➢Without/ But for your help……2.我那天生病了，否则，我就参加运动会了。
If I had not been ill that day, I would have taken part in the sports meeting.➢I would have taken part in the sports meeting, but I was ill that day.➢I was ill that day. Otherwise, I would have taken part in the sports meeting.四、特殊句式1. 馒头-面条原理用于表示建议，决定，命令等词语后的that-从句①用在suggest(建议)，insist(坚决要求)，order(命令，下令)，advise(劝告，忠告)，propose(提议，建议)，recommend(劝告，建议)和require(法规要求，规定)等动词之后的that-宾语从句中，从句谓语动词用（should）+动词原形。
1.He suggested that we (should) start off early the next day.2.They insisted that the boy (should) go with them.3.He advised that she (should) wait for a few weeks.4.We proposed that someone neutral (should) take the chair.5.Teachers recommend parents (should) not allow their children under 12 to ride bicycles toschool for safety.注意：当suggest 表示“暗示”，“表明”之意，insist表示“坚持认为”，后面的宾语从句不用虚拟语气。