高考英语 语法复习 用虚拟条件句表“假设”.doc

用虚拟条件句表“假设”4条件句有两类，一类是真实条件句，一类是虚拟条件句。如果假设的情况是有可能发生的，就是真实条件句。真实条件句中的谓语用陈述语气。if it doesnt rain tomorrow, we will go to the park. 如果明天不下雨，我们就去公园。网搜高中英语语法通霸如果假设的情况是过去或现在都不存在的，或将来不大可能发生的，则是虚拟条件句。if he had seen you yesterday, he would have asked you about it. 如果他昨天见到你，他会问你这件事的。（事实上他昨天没见到你，因此也未能问你这件事。）虚拟条件句分三种情况：与现在相反，与过去相反，与将来相反。其从句和主句的谓语形式如下：时 间if 条件句主 句过 去had donewould /should /could /might have done现 在did （were）would /should /could /might do将 来should do were to do did （were）would /should/could/might do注：would, should, could与might的选择： 一般常用would，如同在真实条件句中主句常要用will一样。常译作“将、就会”。如：if i knew him, i would ask him for help. 如果我认识他的话，我就会向他求助。 should在虚拟条件句中用得最少，现在几乎不用。可能是因为在陈述语气中第一人称后面可以用shall，所以在虚拟语气中，理论上讲，第一人称后也可用should。但在现代英语中，特别是美语中，人们常说：ill go home.或i will go home. 但很少人说i shall go home. 因此，在虚拟条件句中，should也很少用。 could用于虚拟条件句中时，有“能够，可能”之意。如：if you had come back a little earlier, you could have seen it yourself.如果你回来得再稍早一点，你就可能亲眼目睹这件事了。 might用于虚拟条件句时，常译作“或许”，表示可能性有，但不敢肯定。如：if i had been there, i might have quarreled with him. 如果我当时在场的话，我或许会和他吵起来。考点1. 表示与现在事实相反if i knew german, i would read the book in the original.1. if it _ so hard, wed go to town. a. isnt raining b. werent raining c. doesnt rain d. has rain2. if there were no water in the world, everything _.a. will dieb. would die c. would have diedd. would have been dead 3. were safer in a train than we would be if we _ any other way.a. traveledb. had traveled c. traveld. have traveled4. why dont you explain it to her?i _ it to her if i thought she would understand.a. would explainb. will explain c. explaind. would have explained5. 【2012湖南】sorry, i am too busy now. if i _time, i would certainly go for an outing with you.a. have hadb. had hadc. haved. had考点2. 表示与过去事实相反you wouldnt have caught a cold if you had put on more clothes.6. if i _ you，i _ to australia with mr. smith. a. had been; would gob. were; had gone c. were; would have goned. am; will go7. 【2010湖南】if he _ my advice, he wouldnt have lost his job.a. followedb. should followc. had followedd. would follow8. 【2012山东】if we _ adequate preparations, the conference wouldnt have been so successful. a. havent madeb. wouldnt make c. didnt make d. hadnt made9. 【2013重庆】it rained cats and dogs this morning. im glad we took an umbrella.yeah, we would have got wet all over if we _.a. hadntb. havent c. didnt d. dont10. 【2013江苏】i should not have laughed if i _ you were serious.a. thought b. would think c. had thought d. have thought考点3. 表示对将来发生情况的怀疑或实现的可能性很小11. what would we do if it _ tomorrow? a. should snowb. would snowc. snow d. will snow12. 【2009天津】this printer is of good quality. if it _ break down within the first year, we would repair it at our expense.a. wouldb. shouldc. couldd. might13. the volleyball match would be put off if it _ tomorrow.a. will rainb. rainsc. rainedd. is rained14. supposing this ship _, do you think there would be enough life jackets for all the passengers? a. was sinkingb. has sunk c. were to sinkd. sunk15. _ today, he would get there by friday.a. was he leavingb. if he is leaving c. were he to leaved. if he leaves16. 【2012安徽】grace doesnt want to move to new york because she thinks if she _ there, she wouldnt be able to see her parents very often.a. livesb. would live c. has livedd. were to live 考点4. should有“万一”之意在与现在相反的虚拟条件句中，从句谓语有三种形式，其中一种为“should+动词原形”，主要是因为should有“万一”之意，表示一件事听起来可能性很小，但也不是完全没有可能。if条件从句谓语由should加动词原形构成时，主句谓语有用虚拟语气的也有不用虚拟语气的。ask her to ring me up if you should see her. 你万一见到她，请让她给我打个电话。 should还常用在for fear that, in case(以防), lest(以防)等引导的状语从句中。17. he is working hard for fear that he _ to pass the exam.a. failsb. may failc. should faild. would fail18. he doesnt dare to leave the house in case _.a. he will recognizeb. he should be recognized c. he is recognizedd. he recognize19. the driver looked over the engine carefully lest it _ on the way.a. breaks downc. would break down b. broke downd. should break down考点5. 错综时间虚拟条件句所谓错综时间虚拟条件句即条件从句与主句所指时间不一致，如从句指过去，而主句却指的是现在或将来，此时应根据具体的语境情况，结合上面提到的三种基本类型对时态作相应的调整。if they had started in the early morning, they would arrive in half an hour.(过去将来; 错综时间虚拟条件句) if they had started in the early morning, they would be here now. (过去现在; 错综时间虚拟条件句)if they had started in the early morning, they would have arrived. (过去过去；不是错综时间虚拟条件句)20. it is hard for me to imagine what i would be doing today if i _ in love，at the age of seven，with the melinda cox library in my hometown. a. wouldnt have fallenb. had not fallen c. should falld. were to fall21. had you listened to the doctor, you _ all right now.a. areb. werec. would bed. would have been22. 【2013北京】if we _ a table earlier, we couldnt be standing here in a queue.a. have bookedb. bookedc. bookd. had booked23. 【2013天津】if he had spent more time practising speaking english before, he _ able to speak it much better now.a. will be b. would be c. has been d. would have been考点6. if 的省略虚拟条件句中有were, had, should时，可把if省略，而把were, had, should放在主语前，用倒装结构，这种结构主要用于书面语中。如： were it necessary, i might resign.should it rain tomorrow, we would have to put off the visit to the summer palace.were there to be a flood, what should we do?had i left a little earlier, i would have caught the train.24. 【2012浙江】 had they known what was coming next, they _ second thoughts.a. may haveb. could have c. must have hadd. might have had25. _ what was going to happen, i would never have left her alone.a. had i knownb. if i knowc. if i knewd. if had i known 26. _ today, he would get there by friday.a. were he to leaveb. if he had left c. did he to leaved. had he left 27. _ the work, he would do it some other way.a. was he goingb. if he does c. were he to dod. if he is doing28. _ the clouds, you would find the airplane in the sky easily.a. had it not been forb. if it were not c. if it had not been ford. were it not for 29. _ any change about the date, please tell me immediately. a. will there beb. should there bec. there will bed. there should be 30. the business is risky. but _ we would be rich.a. should we succeedb. we should succeed c. might we succeedd. would we succeed考点7. 用was还是用were在当代英语中，尤其在口语中，单数主语常用was代替虚拟式were。如： i wish i was ten years younger. 我但愿年轻10岁。在含义上，有时was发生的可能性大于were。如： he looks as if he was ill. 他像是病了。 但在倒装虚拟结构及if i were you, as it were中，只能用were。如： were i ten years younger, i would study abroad. 要是我还年轻10岁的话，我会去国外学习。if i were you, i would try my best to grasp the chance. 要是我是你的话，我要尽力抓住这次机会。as it were“可以说，在某种程度上”。英语解释为：as if it were really so。he is, as it were, a walking dictionary.他可以说是一部活字典。he became, as it were, a man without a country.他在某种程度上成了一个无国籍的人。但在正式文体中仍须用were。在考试中最好还是用were。考点8. 根据主句谓语或从句谓语判断是否是虚拟语气一般情况下，从句和主句要用陈述语气都用陈述语气，要