虚拟语气一. 虚拟语气在条件状语从句中的应用虚拟语气(Subjunctive Mood)这一语法项目几乎是四、六级必考的内容，也是各类英语考试中心测试的重点之一。
虚(win the first prize)的话，我会把奖金送给阿Sam。
If I won/should win/were to win the first prize in the Foshan University Students English Speaking Contest held in May, I would give my reward to Sam.If I win the first …, I will give …要是我爸是李嘉诚的话，我一定不用为钱发愁。
If my father were Li Jia Cheng, I wouldn’t worry about money.Were my father Li Jia Cheng, I wouldn’t …要是日本没有发生地震的话，我一定去放炸弹(blast)。
If Japan hadn’t had the earthquake, I would have blasted it.Hadn’t Japan had the earthquake, I …1要是将来我有钱了，我一定回来娶你。
If I were rich one day, I would marry you.→Were I rich one day, I …If I should be rich one day, I would marry you.→Should I be rich one day, I …If I were to be rich one day, I would marry you.→Were I to be rich one day, I …(If I am rich one day, I will marry you.)1. 虚拟现在时表示与现在事实相反的假设，其if 从句的谓语形式用动词的过去式(be 一般用were)，主句用would/ should/ could/ might +动词原形。
1) If places ______ a like, there would be little need for geographers.A. beingB. areC. beD. were2) If I _____ the meaning of the word, I wouldn't have to look it up.A. knowB. knewC. knownD. knowing2. 虚拟过去时是表示与过去事实相反的假设，if 从句的谓语形式用过去完成时即had＋过去分词，主句用would / should / could / might + have +过去分词。
例：1995年6月四级第46题We didn't know his telephone number, otherwise we _____ him,A) would have telephoned B) must have telephonedC) would telephone D) had telephoned3. 虚拟将来时是表示对将来实现的可能性很小的或不确定的假设。
If从句的谓语形式用一般过去式或用were to / should +动词原形，主句用would / should /could/ might +动词原形。
2例：1996年1月四级第44题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.A. has to getB. had gotC. were to getD. could have got※二. 省略If的几种情况1. 当条件状语从句的谓语部分含有had、should、或were时，就将这样的词had、should、或were搬到句首把句子写成倒装句而将连词if省略。
例如：If you were the manager here, what would you do? 你若是这里的经理，你会怎么办？If he should act like that again, he would be fired immediately. 要是他再那样做，他会被立即解雇的。
2. 由某些介词短语取代了if引导的条件状语从句。
例如：Without air, there would be no life on the earth. 要是没有空气，地球上就不会有生命了。
But for your help, the little boy would have been drowned. 要是没有你们的帮助，那个小男孩早就淹死了。
We could have done the work better in that case. 要是那样的话，我们本可以把工作干得更好一些的。
3. 由上下文的交代而省略了if引导的条件状语从句。
在这种情况下，上下文事实上就是一个表示违背事实的条件句。
上下文如果是由一个句子介绍的，那么这个取代了if条件状语从句的句子应该用直陈语气；而起主句作用的句子则要用虚拟语气。
例如：He would have come to see you earlier but he just came back from his business trip .（本句中的上下文是：but he just came back from his business trip，表示：要是他在家没出差的话）他本来早就来看你了，可他却3出差刚刚回来。
But that you helped me, I would have failed in the experiment. （本句中的上下文是：But that you helped me，表示：要不是有你帮助我）要没有你帮助我，我的试验本做不成功的。
三. 虚拟语气的其它应用1. 在具有愿望、请求、建议、命令等主观意愿的动词(desire, demand, advise, insist, require, suggest, propose, order, recommend, decide …) 后的宾语从句中需用虚拟语气。
谓语动词用(should) +动词原形。
例：1996年1月四级第28题It is politely requested by the hotel management that radios ______ after 11 o'clock at night.A. were not playedB. not be playedC. not to playD. did not play十八岁以下的未成年人不得观看限制级影片。
It is required that people under 18 shouldn’t watch/see X-rated films.→It is required that people under 18 not watch/see X-rated films.在电梯(elevator/lift)里不得吸烟。
It is required that smoking shouldn’t be allowed in the elevator.→It is required that smoking not be allowed in the elevator.在火警发生时，不得使用电梯。
It is required that the elevator shouldn’t be used in case of fire.→It is required that the elevator not be used in case of fire.2. 虚拟语气在表语从句和同位语从句中的应用在表示建议、请求、命令等主观意向的名词(suggestion, proposal, requirement, demand, desire, advice, order, insistence…) 作主语时，其后的表语从句或同位语从句中，需用虚拟语气。
谓语动词用(should)+动词原4形。
注意这种句型中的虚拟语气形式不受主句动词时态的影响。
例：1998年6月四级第68题We are all for your proposal that discussion _____.A. be put offB. was put offC. should put offD. is to put off3. 在if only 引起的感叹句中需用虚拟语气。
谓语动词用过去式或过去完成式。
例：1993年6月四级第70题Look at the terrible situation I am in! If only I ____ your advice.A. followB. had followedC. would followD. have followedExercise1．If I were to have (have) time, I would join (join) you in the football match.If I had had time, I would have joined you in the football match.If I had time, I would join you in the football match.If I have time, I will join you in the football match.2．If I hadn’t been caught (not catch) by something, I would have come (come) to your party yesterday.3．If he had taken (take) my advice, he wouldn’t have made (not make) such a bad mistake.4．It is necessary that he should be send (send) to Beijing right away.5．If only I knew (know) the numbers of the next lottery!6．If the machine had been (be) in good conditions, we could/would have used (use) it in our last experiment.5。