高中英语语法-虚拟语气全总结-标准化文件发布号：（9556-EUATWK-MWUB-WUNN-INNUL-DDQTY-KII①错综时间条件句:当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为错综时间条件句，动词的形式要根据它表示的时间作出相应的调整。
如：If you had followed my advice just now, you would be better now.If you had studied hard before, you would be a college student now.②if省略句在条件句中可以省略if, 把were, had, should提到句首，变成倒装句式。
如：If I were at school again, I would study harder.→Were I at school again, I would study harder.如果我还有上学的机会，我会更加努力学习。
If you had come earlier, you would catch the bus.→Had you come earlier, you would catch the bus.如果你来得早点，你就能赶上公共汽车。
If it should rain tomorrow, we would not go climbing.→Should it rain tomorrow, we would not go climbing.如果明天下雨的话，我们就不能登山去了。
③用介词代替条件状语从句常用的介词有with, without, but for。
如：What would you do with a million dollars (=if you had a million dollars)如果你有100万元，你会做什么？We couldn’t have finished the work ahead of time without your help. (=if we hadn’t got your help)没有你的帮助，我们不可能提前完成这项工作。
Without your help, we couldn’t have finished the work ahead of time.= But for your help, …= If it had not been for your help, …= Had it not been for you help, …没有你的帮助，我们不可能提前完成这项工作。
④含蓄条件句有时在虚拟语气中并不总是出现if引导的条件句，而是通过其他手段来代替条件句。
如：I was ill that day. Otherwise, I would have taken part in the sports meeting. (副词)He telephoned to inform me of your birthday, or I would have known nothing about it. (连词) A man who stopped drinking water would be dead in about seven days. (定语从句)I might have given you more help, but I was too busy. (连词)Everything taken into consideration, they would have raised their output quickly. (独立主格结构)⑤even if, even though也可用于虚拟语气，其形式与if 从句在虚拟语气中的形式相同。
习题1. If my lawyer＿＿＿here last Saturday, he＿＿＿me from going.A.had been, would have preventedB.had been, would preventC.were, would preventD.were, would have prevented2. If it＿＿＿for the snow, we＿＿＿the mountain yesterday.A.were not, could have climbedB.were not, could climbC.had not been, could have climbedD.had not been, could climb3. Without electricity(电) human life＿＿＿quite difficult today.A. isB. will beC. would have beenD. would be4. I didn’t see your sister at the meeting, if she＿＿＿, she would have met my brother.A. has comeB. did comeC. cameD. had come5. When the pencil is partly in a glass of water, it looks as if it＿＿＿.A. breaksB. has brokenC. were brokenD. had been broken6. He hesitated(犹豫) for a moment before kicking(踢) the ball. Otherwise he＿＿＿a goal.A. had scoredB. scoredC. would scoreD. would have scored7. ＿＿＿right now, she would get there on Sunday.A.Would she leaveB.If she leavesC.Were she to leaveD.If she had left8. Had he worked harder, he＿＿＿the exam.A.must have got throughB.would have got throughC.would get throughD.could get through9. He must have had an accident, or he＿＿＿then.A.would have been hereB.had to be hereC.should be hereD.would be here10. ＿＿＿for my illness I would have lent him a helping hand.A.Not beingB.Had it not beenC.Without beingD.Not having been11. We didn’t know his telephone number, otherwise we＿＿＿him.A.would have calledB.must have telephonedC.would telephoneD.had telephoned虚拟语气(1)复习题1.He ＿＿＿ you more help, even though he was very busy.A. might have givenB. might giveC. may have givenD. may give2.＿＿＿ for your laziness(懒惰), you could have finished the assignment(任务) by now.A. Had it not beenB. It were notC. weren’t itD. Had not it been3.If I hadn’t stood under the ladder(梯子) to catch you when you fell, you ＿＿＿now.A. wouldn’t be smilingB. couldn’t have smiledC. won’t smileD. didn’t smile4.If it ＿＿＿ Professor Johnson’s recommendation(推荐), I wouldn’t have been admitted to the graduate school(研究生学院).A. were not forB. had not been forC. were notD. had it not been5.If we do not develop a new kind of car, air pollution ＿＿＿ even more dangerous.A. should have becomeB. will becomeC. would have becomeD. must have become6.But for the stormy weather, we ＿＿＿ earlier.A. should arriveB. shall arriveC. should have arrivedD. shall have arrived7.If we ＿＿＿ their terms(条款，条件), we would go bankrupt(破产).A. acceptB. should acceptC. had acceptedD. are to accept8.John would never have gone to the hospital ＿＿＿ that Tom would be there, too.A. he did not knowB. if had he knownC. had he knownD. he would have known9.Had he been more careful, he ＿＿＿ that accident.A. would avoidB. would have avoidedC. avoidedD. should avoid10.But that he came to help me, I ＿＿＿ there earlier.A. could not arriveB. could not have arrivedC. did not arriveD. can not arrive11.She could look more attractive(有魅力的，吸引人的) but she ＿＿＿ no attention to her clothes.A. paysB. was payingC. paidD. had paid12.If I ＿＿＿ in his place, I would do that, too.A. wasB. wereC. amD. had been虚拟语气(2)——虚拟语气在名词从句中1.在由suggest, demand, require, request, insist, order, command, propose等表示建议、请求、命令、愿望等动词或其同根词引出的名词从句中，名词从句虚拟句的谓语变化的形式只有一条规律——名词从句虚拟句无论其主句的谓语动词时何种形式，从句的谓语形式均为should+动词原形，其中should可以省去。