if 引导的非真实性条件状语从句即虚拟语气通过动词形式的变化来表示说话人对发生的动作或存在的状态所持的态度或看法的动词形式称为语气。

.英语中的语气分三种：陈述语气、祈使语气、虚拟语气。

虚拟语气表示说话人所说的话不是事实，而是一种祝愿，建议，与事实相反的假设或实际可能性不大的情况等（即非真实的假设）。

If 引导的条件状语从句分为真实和非真实条件句（虚拟条件句）。

真实条件句表示在假设的条件下，有可能实现的情况。

非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。

If he does n’t hurry up, he will miss the bus.( 真实条件状语)If he was free, he asked me to tell stories.（真实条件状语）If I were you, I would go at once.（非真实条件状语从句）If there was no air, people would die.（非真实条件状语从句）1）非真实条件句中虚拟语气的基本形式。

假设类型条件从句的动词结果主句的动词与现在事实相反动词过去式（be只用were）would/should/could/might + 动词原形与过去事实相反had+过去分词would/should/could/might + have + 过去分词与将来事实相反动词过去式/(should/were to)+动词原形would/should/could/might + 动词原形①与现在事实相反If I had time, I would go for a walk.如果我有时间，我就会去散步。

(实际情况：我现在没有时间，也不会去散步。

)If I were you, I would take an umbrella.假如我是你的话，我会带上雨伞。

(事实上我不可能是你。

)I would say no if someone asked me to be in a movie.假如有人请我当电影演员，我会表示拒绝。

(事实上现虚拟语气专项练习1．Were it not for the snowy weather, we __________all right.A. would beB. would have beenC. wereD. may be2. ________more careful, his ship would not have sunk.A. If the captain wereB. Had the captain beenC. Should the captain beD. If the captain would have been3. If he _________ me tomorrow, I would let him know.A. should callB. should not have been ableC. were not ableD. are not able4.If you asked your father, you ______________ permission.A. may getB. might getC. should have calledD. maybe get5._____________today, he would get there by Friday.A. Would he leaveB. was he leavingC. Were he to leaveD. If he leaves6.______I you, I would go with him to the party.A. WasB. Had beenC. Will beD. Were7.The millions of calculations involved, had they been done by hand, __________all practical value by the time they were finished.A. could loseB. would have lostC. might loseD. ought to have lost8.Had Paul received six more votes in the last election, he ________our chairman now.A. must have beenB. would have beenC. wereD. would be9.If you ________________Jerry Brown until recently, you'd think the photograph on the right was strange.A. shouldn't contactB. didn't contactC. weren't to contactD. hadn't contacted10.____________he English examination I would have gone to the concert last SundayA. In spite ofB. But forC. Because ofD. As for11.Look at the terrible situation I am in! If only I _____________your adviceA. followB. would followC. had followedD. have followed12.Had Paul received six more votes in the last election, he ____________our chairman now.A. must have beenB. would have beenC. wereD. hadn't contacted13.If the horse won today, it _____________ thirty races in five years.A. would have wonB. wonC. must have wonD. did have won14. There is a real possibility that these animals could be frightened, _______a sudden loud noise.A. being thereB. should there beC. there wasD. there having been17.I would have gone to visit him in the hospital, had it been at all possible, but I ______ fully occupied the whole of last week.A. wereB. had beenC. have beenD. was18.I apologize if I __________ you, but I assure you it was unintentional(无意的).A. offendB. had offendedC. should have offendedD. might have offended19. If you hadn't taken such a long time to get dressed, we'd______________ there by now.A. beB. circlesC. is circlingD. be circling20. The sun rises in the east and sets in the west, so it seems as if the sun ________round the earth.A. were circlingB. circlesC. is circling D . be circling21. I wish that I _______________ with you last night.A. wentB. have goneC. could goD. could have gone22. I wish I ___________ with her.A. would beB. amC. wasD. were23. I wish that I_____________ the concert last night.A. couldB. have attendedC. could have attendedD. attended24. The picture exhibition bored me to death. I wish I_______________ to it.A. had not goneB. have not goneC. did not goD. can not have gone25. "I wish you___________ me to put these things away," he said.A. will helpB. helpC. are helpingD. would help26. If the Watergate Incident_____________ Nixon would nothave resigned from the presidency.A. did not occurB. had not occurredC. was not occurringD. be circling27. I hadn't expected ________James to apologize but I had hoped .A. him calling meB. that he would call meC. him to call meD. that he call me28. George would certainly have attended the meeting, ____________________ .A. if he didn't get a flat tireB. if the flat tire hadn't happenedC. had he not had a flat tireD. had the tire not flattened itself29. The teacher suggested that her students _____________ experiences with ESP.A. write a composition on theirB. to write composition about theC. wrote some compositions of his or herD. had written any compositions for his30. He speaks Chinese as fluently as if he ______________a Chinese.A. wereB. had beenC. isD. has been31. As usual, he put on a show as though his trip____ a great success.A. had beenB. has beenC. wereD. was32. Looking round the town, he felt as though he ______________ away for ages.A. has beenB. wasC. isD. had been33. John is so strongly built that he looks as if he ______as elephant.A. liftsB. is liftingC. LiftedD. could lift34. He described the town as if he_____________ it himself.A. had seenB. has seenC. sawD. sees35. At that thought he shook himself, as though he _____________from an evil dream.A. wokeB. wakesC. would wakeD. had woke36. Most insurance agents would rather you ___________ anything about collecting claims until they investigate the situation.A. doB. don'tC. didn'tD. didn't do37. Although most adopted persons want the right to know who ______________their natural parents are, some who have found them wish that they the experience of meeting.A. hadn'tB. didn't have hadC. hadn't hadD. hadn't have38. It is important that the TOEFL office ________ your registration.A. will confirmB. confirmC. confirmsD. must confirm39. without electronic computers, much of today's ___________advanced technology.A. will not have been achievedB. have not been achievedC. would not have been achievedD. had not been achieved40. He speaks Chinese as fluently as if he ____________a Chinese.A. wereB. had beenC. isD. has been41. It is time that the government ______________measures to protect the rare birds and animals.A. takesB. tookC. has takenD. taking42. Some people are too particular about school records, insisting that every applicant ___all diplomas from elementary school to university.A. hasB. will haveC. should haveD. must have43. He was very busy yesterday, otherwise he _____ to the meeting.A. would comeB. CameC. would have comeD. had come44. I must say he reads very well, and I shouldn't be surprised if he___________ acting for a living one day.A. had taken upB. takes upC. have taken upD. would have taken up45. If I had seen the movie, I ______________ you all about it now.A. would tellB. will tellC. have toldD. would have told46. I hadn't expected ______Henry to apologize but I had hoped .A. him to call me upB. him calling me upC. that he would call me upD. that he will call me47. I had hoped that John ____________a year in Africa, but he stayed there only for three months.A. spendsB. spentC. would spendD. will spend48. I had hoped that Jennifer___________ a doctor, but she wasn't good enough at science.A. will becomeB. becameC. would becomeD. becomes49. I'd rather you ___________ anything about it for the time being.A. doB. didn't doC. don'tD. didn't50. I'd just as soon_______ rudely to her.A. that you won't speakB. you not speakingC. you not speakD. you didn't speak51. It's high time they____________ this road.A. mendB. mendedC. must have mendedD. will mend52. It's about time people______ notice of what women did during the war.A. takeB. tookC. have takenD. will take53. Everybody has arrived. It's time we___________ the class.A. shall startB. would startC. had startedD. start54. ___________ the English examination I would have gone to the concert last Sunday.A. In spite ofB. But forC. Because ofD. As for55. Mary ___my letter; otherwise she would have replied before now.A. has receivedB. ought to have receivedC. couldn't have receivedD. shouldn't have received56. John did not feel well yesterday; otherwise he _______to see his classmates off.A. cameB. would comeC. would have comeD. should be coming57. He's working hard for fear that he_____________ .A. should fall behindB. fell behindC. may fall behindD. would fall behind58. Without the dreams of the youth, this invention might____________ for a century.A. have been postponedB. has been postponedC. postponeD. be postponed59. In the past men generally preferred that their wives_______________ in the home.A. workedB. would workC. workD. were working60. For a child to give up his less mature idea for a more mature one, it requires that the child _____psychologically ready for the new idea.A. isB. wereC. beD. would be61. Tom's father, as well as his mother,_______________ in New York for a few days more.A. ask him to stayB. ask he to stayC. asks he staysD. asks he stay62. Your advice that_____________ till next week is reasonable.A. she waitsB. she waitC. wait sheD. she waited64. It was essential that we lease before the end of the month.A. singB. singedC. had signedD. were signing65. It is appropriate that some time ______thorough study of the results of the Apollo mission.A. devotes toB. devoted toC. is devoted toD. be devoted to答案与详解1．A．条件句表示与现在事实相反的虚拟。