一、考點聚焦
1、虛擬語氣用于條件狀語從句中
（1）表示與現在事實相反的假設，條件狀語從句中的謂語動詞用“過去式（be動詞的過去式用were）”，而主句中的謂語動詞用“would / should/ could / might + 動詞原形”。如：
If I were a boy, I would join the army.
If the had time, she should go with you.
（2）表示與過去的事實相反，條件狀語從句中的謂語動詞用過去完成時，主句中的謂語動詞則用“would / should / might / could + have +過去分詞”。如：
If he had taken my advice, he would have succeeded in the competition.
（3）表示與將來事實相反，條件狀語從句中的謂語動詞一般過去時或should(were to) + 動詞原形，而主句中的謂語動詞則用would / should/
could might + 動詞原形。如；
If it were to rain tomorrow, the football match would be put off.
（4）當條件狀語從句表示的行為和主句表示的行為所發生的時間不一致時，動詞的形式要根據它所表示的時間作相應調整。如：
If they had worked hard, they would be very tired.(從句說的是過去，主句指的是現在)
以下表格是虛擬語氣用于條件狀語從句中時，主句和從句謂語動詞的形式：
條件狀語從句 主 句
與過去事實相反 had + 過去分詞 should /would/could/might + have + 過去分詞
與現在事實相反 一般過去時(be用were) would/should/could/might + 動詞原形
與將來事實相反 一般過去時或should(were to) + 動詞原形 Would/should/cold/might + 動詞原形
有時侯在使用時可省略if,句子則可換成下列形式，即“were / had / should +主語”。如：
Were I a boy, I would join the army.
Had he taken my advice, he would have succeeded.
Were it not for the expense, I would go to Britain.
2、虛擬語氣用于名詞性從句
（1）虛擬語氣在賓語從句中的運用。
①“wish + 賓語從句”表示不能實現的愿望，譯為“要是……就好了”等。表示現在不能實現的愿望，從句中的謂語動詞用一般過去時；表示將來不能實現的愿望，從句中的謂語動詞用“would/could + 動詞原形”；表示過去不能實現的愿望，從句中的謂語動詞用“had + 過去分詞”或“could(should) + have + 過去分詞”。如：
I wish it were spring all the year round.
I wish I had known the answer.
I wish I could fly like a bird.
②在表示建議、要求、命令等的動詞suggest、advise、propose、demand、require、insist request、command、order等后的賓語從句中，謂語動詞用should + 動詞原形或是動詞原形。如：
She suggested we (should)leave here at once.
The doctor ordered she should be operated.
（2）虛擬語氣在同位語從句和表語從句中的運用。
作表示建議、要求、命令等的名詞advise、idea、order、demand、plan、proposal、suggestion、request等的表語從句和同位語從句，從句中的謂語動詞用“（should） + 動詞原形”。如：
His suggestion that we (should)go to Shanghai is wonderful.
My idea is that they (should)pay 100 dollars.
（3）虛擬語氣在主語從句中的運用。
在主語從句中，謂語動詞的虛擬語氣用“should + 動詞原形”的結構，表示驚奇、不相信、理應如此等。如：
It is necessary(important, natural, strange, etc.)that we should clean the room every day.
It was a pity (a shame, no wonder, etc.)that you should be so careless.
It will be desired(suggested, decided, ordered, requested, proposed, etc.)that she should finish her homework this afternoon.
注意：這種從句表示的是事實。如果說人對這種事實表現出驚奇的情感，就可用虛擬語氣。反之，如果不表示驚奇等情感，that從句也可用陳述句語氣。如：
It is pity that you can’t swim.
3、虛擬語氣在其他場合的運用
（1）虛擬語氣在as if/as though、even if/even though等引導的表語從句或狀語從句中，如果從句表示的動作發生在過去，用過去完成時；指現在狀況，則用一般過去時；指將來狀況則用過去將來時。如：
He did it as if he were an expert.
Even if she were here, she could not solve the problem.
（2）虛擬語氣用于定語從句中。
這種從句常用于句型“It is (high)time (that) … ”中，定語從句的謂語動詞用一般過去時(be用were)或should + 動詞原形，意思是“(現在)該……”。如：
It’s time that I picked up my daughter.
It’s high time we were going.
（3）虛擬語氣用在if only引導的感嘆句中。如：
If only I were a bird.
If only I had taken his advice.
（4）虛擬語氣在一些簡單句中的運用。
①情態動詞的過去式用于現在時態時，表示說話人謙虛、客氣、有禮貌或語氣委婉，常出現在日常會話中。如：
It would be better for you not to stay up too late.
Would you be kind enough to close the door?
②用于一些習慣表達法中。如：
Would you like a cup of tea?
I would rather not tell you.
二、精典名題導解
選擇填空
1. When a pencil is partly in a glass of water, it looks as if it _______. (NMET 95)
A.breaks B.has broken C.were broken D.had been broken
解析：答案為C。本題考查的是as if 引導的讓步狀語從句中的語氣問題，as if引導的狀語從句如果與事實一致，不用虛擬語氣，如果與事實相反，應用虛擬語氣。題中“當鉛筆的一部分浸在水中，鉛筆看上去好像斷了”。而實際上鉛筆并未斷，與事實相反，前半部分陳述是一般現在時，因而本句是對一般現在時的虛擬，用were broken。
2. I didn’t see your sister at the meeting. If she ___________, she would have met my brother.(NMET 94)
A.has come B.did come C.came D.had come
解析：答案為D。本題考查的是if條件句中的虛擬語氣。題意是：我在會議上沒看到你姐姐，故你姐姐沒來。因此如果“她來了”與事實相反，前面一句交代了虛擬語氣的時態是一般過去時的虛擬，所以if從句中用had+過去分詞。
3. -If he ___________, he ________that food.
-Luckily he was sent to the hospital immediately.(NMET 93)
A.was warned; would not take
B.had been warned; would not have taken
C.would be warned; had not taken
D.would have been warned; had not taken
解析：答案為B。本題考查的是條件狀語從句與主句表示與事實相反時虛擬語氣的用法。根據下一句語境可知，他事先并沒有得到警告，表示過去時間的虛擬語氣，故選B。
虛擬語氣專項練習
1．Were it not for the snowy weather, we __________all right.
A. would be B. would have been C. were D. may be
2. ________more careful, his ship would not have sunk.
A. If the captain were B. Had the captain been
C. Should the captain be D. If the captain would have been
3. If he _________ me tomorrow, I would let him know.
A. should call B. should not have been able
C. were not able D. are not able
4. If you asked your father, you ______________ permission.
A. may get B. might get C. should have called D. maybe get
5. _____________today, he would get there by Friday.
A. Would he leave B. was he leaving
C. Were he to leave D. If he leaves
6. ______I you, I would go with him to the party.
A. Was B. Had been C. Will be D. Were
7. The millions of calculations involved, had they been done by hand, __________all practical value by the time they were finished.
A. could lose B. would have lost
C. might lose D. ought to have lost
8. Had Paul received six more votes in the last election, he ____________our chairman now.
A. must have been B. would have been C. were D. would be
9. If you ________________Jerry Brown until recently, you’d think the photograph on the right was strange.
A. shouldn’t contact B. didn’t contact
C. weren’t to contact D. hadn’t contacted
10. ____________he English examination I would have gone to the concert last Sunday
A. In spite of B. But for C. Because of D. As for
11. Look at the terrible situation I am in! If only I _____________your advice
A. follow B. would follow C. had followed D. have followed
12. Had Paul received six more votes in the last election, he ____________our chairman now.
A. must have been B. would have been
C. were D. hadn’t contacted
13. If the horse won today, it _____________ thirty races in five years.
A. would have won B. won C. must have won D. did have won
14. There is a real possibility that these animals could be frightened, _______a sudden loud noise.
A. being there B. should there be
C. there was D. there having been
17. 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. were B. had been C. have been D. was
18. I apologize if I __________ you, but I assure you it was unintentional(無意的).
A. offend B. had offended
C. should have offended D. might have offended
19. If you hadn’t taken such a long time to get dressed, we’d______________ there by now.
A. be B. circles C. is circling D. be circling
20. The sun rises in the east and sets in the west, so it seems as if the sun ________round the earth.
A. were circling B. circles C. is circling D. be circling
21. I wish that I _______________ with you last night.
A. went B. have gone C. could go D. could have gone
22. I wish I ___________ with her.
A. would be B. am C. was D. were
23. I wish that I_____________ the concert last night.
A. could B. have attended C. could have attended D. attended
24. The picture exhibition bored me to death. I wish I_______________ to it.
A. had not gone B. have not gone
C. did not go D. can not have gone
25. “I wish you___________ me to put these things away,” he said.
A. will help B. help C. are helping D. would help
26. If the Watergate Incident_____________ Nixon would not have resigned from the presidency.
A. did not occur B. had not occurred C. was not occurring D. be circling
27. I hadn’t expected ________James to apologize but I had hoped .
A. him calling me B. that he would call me
C. him to call me D. that he call me
28. George would certainly have attended the meeting, ____________________ .
A. if he didn’t get a flat tire B. if the flat tire hadn’t happened
C. had he not had a flat tire D. had the tire not flattened itself
29. The teacher suggested that her students _____________ experiences with ESP.
A. write a composition on their B. to write composition about the
C. wrote some compositions of his or her D. had written any compositions for his
30. He speaks Chinese as fluently as if he ______________a Chinese.
A. were B. had been C. is D. has been
31. As usual, he put on a show as though his trip____ a great success.
A. had been B. has been C. were D. was
32. Looking round the town, he felt as though he ______________ away for ages.
A. has been B. was C. is D. had been
33. John is so strongly built that he looks as if he ______as elephant.
A. lifts B. is lifting C. lifted D. could lift
34. He described the town as if he_____________ it himself.
A. had seen B. has seen C. saw D. sees
35. At that thought he shook himself, as though he _____________from an evil dream.
A. woke B. wakes C. would wake D. had woke
36. Most insurance agents would rather you ___________ anything about collecting claims until they investigate the situation.
A. do B. don’t C. didn’t D. didn’t do
37. 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’t B. didn’t have had C. hadn’t had D. hadn’t have
38. It is important that the TOEFL office ________ your registration.
A. will confirm B. confirm C. confirms D. must confirm
39. without electronic computers, much of today’s ___________advanced technology.
A. will not have been achieved B. have not been achieved
C. would not have been achieved D. had not been achieved
40. He speaks Chinese as fluently as if he ____________a Chinese.
A. were B. had been C. is D. has been
41. It is time that the government ______________measures to protect the rare birds and animals.
A. takes B. took C. has taken D. taking
42. Some people are too particular about school records, insisting that every applicant ___all diplomas from elementary school to university.
A. has B. will have C. should have D. must have
43. He was very busy yesterday, otherwise he _____ to the meeting.
A. would come B. came C. would have come D. had come
44. I must say he reads very well, and I shouldn’t be surprised if he___________ acting for a living one day.
A. had taken up B. takes up C. have taken up D. would have taken up
45. If I had seen the movie, I ______________ you all about it now.
A. would tell B. will tell C. have told D. would have told
46. I hadn’t expected ______Henry to apologize but I had hoped .
A. him to call me up B. him calling me up
C. that he would call me up D. that he will call me
47. I had hoped that John ____________a year in Africa, but he stayed there only for three months.
A. spends B. spent C. would spend D. will spend
48. I had hoped that Jennifer___________ a doctor, but she wasn’t good enough at science.
A. will become B. became C. would become D. becomes
49. I’d rather you ___________ anything about it for the time being.
A. do B. didn’t do C. don’t D. didn’t
50. I’d just as soon_______ rudely to her.
A. that you won’t speak B. you not speaking
C. you not speak D. you didn’t speak
51. It’s high time they____________ this road.
A. mend B. mended C. must have mended D. will mend
52. It’s about time people______ notice of what women did during the war.
A. take B. took C. have taken D. will take
53. Everybody has arrived. It’s time we___________ the class.
A. shall start B. would start C. had started D. start
54. ___________ the English examination I would have gone to the concert last Sunday.
A. In spite of B. But for C. Because of D. As for
55. Mary ___my letter; otherwise she would have replied before now.
A. has received B. ought to have received
C. couldn’t have received D. shouldn’t have received
56. John did not feel well yesterday; otherwise he _______to see his classmates off.
A. came B. would come C. would have come D. should be coming
57. He’s working hard for fear that he_____________ .
A. should fall behind B. fell behind
C. may fall behind D. would fall behind
58. Without the dreams of the youth, this invention might____________ for a century.
A. have been postponed B. has been postponed
C. postpone D. be postponed
59. In the past men generally preferred that their wives_______________ in the home.
A. worked B. would work C. work D. were working
60. 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. is B. were C. be D. would be
61. Tom’s father, as well as his mother,_______________ in New York for a few days more.
A. ask him to stay B. ask he to stay
C. asks he stays D. asks he stay
62. Your advice that_____________ till next week is reasonable.
A. she waits B. she wait C. wait she D. she waited
64. It was essential that we lease before the end of the month.
A. sing B. singed C. had signed D. were signing
65. It is appropriate that some time ______thorough study of the results of the Apollo mission.
A. devotes to B. devoted to C. is devoted to D. be devoted to
答案與詳解
1．A．條件句表示與現在事實相反的虛擬。
2．B．條件句表示與過去事實的虛擬。
3．A．條件句表示與未來事實的虛擬。
4．B．條件句表示與未來事實的相反。
5．C．條件句表示與現在事實的虛擬。
6．D．條件句表示與現在事實的虛擬。
7．B．這個句子中含有一個省略if，把助動詞提前到主語they之前的虛擬條件句，該條件句表示對過去情況的假設，而主句中by the time they were finished 表明主句也應該是對過去發生的情況的假設，因而應該選（B）would have lost為正確答案。
8．（D）這道題目是一個混合虛擬語氣的句子。條件句省略了if，把助詞had提前到主語前面，表示對過去情況的假設，而主句中now表明了對現在情況的假設，所以應選would(should, could, might)+動詞原形這種表達形式。四個選項中只有（D）是正確表達形式，故為正確答案。
9．（D）until recently，因此（D）是正確答案，而主句是隱含的對現在情況的假設，該句是一個混合虛擬條件句。
10．（B）假設的情況有時不是用一個條件句表示，而是隱含在一個由介詞如but for、but that、without, 由連詞but、副詞otherwise 、比較級、形容詞、獨立主格等表示的上下文中。本句主句表示對過去情況的假設，但事實上由于英語考試而沒有去成，即若不是因為英語考試，我本可以去聽音樂會，所以應選But for為正確答案。
11．（C）題目中的第一句話表示的是現在真實的情況，而第二句話中所要表達的是應該做但事實上沒有做的事，這種情況導致第一句話中真實情況的發生，故If only條件句假設的是過去一種情況，因此應該用had +過去分詞，所以正確答案是（C）。
12．D．注意主句now表示現在的時間狀語，所以主句是對現在虛擬，從句是對過去虛擬。
13．A．從句對過去的虛擬。
14．B．從句表示虛擬，而主句是事實。
17．（D）本道題目的前半句話是對過去情況的一種假設，但事實上并沒有發生，而事實上沒有發生的真實原因是句子的后半部分由but引導的轉折句所表述的真實。因而but所引導的句子中應該用表示志過去事實相符合的表陳述的時態，即一般過去時。
18．（B）此題要求在if從句中選擇適當的動詞形式，以主句中的動詞apologize(抱歉)來看，if從句中表達的內容應該是過去做的事，因此可以排除（A），因為（A）是現在時。（C）中should+have+過去分詞結構表示本來應該做卻沒有做的事，在此不合題意。（D）選項中的might+have+過去分詞表示對過去發生的事情很不肯定的猜測，它表達的內容還不能成為事實，所以藉此道歉真是不知從何說起，因此此處也不合題意。（B）had offended表示當時已經發生了的動作。這是復雜條件句：apologize 是現在，而條件句是表示對過去假設的條件句。
19．（A）該句也是一個復雜條件句（或稱作混合虛擬條件句）。條件句表示對過去情況的假設，而主句表示對現在情況的假設，但事實上卻與此相反，所以正確答案應該是（A）。
20．（A）as if引導的從句要求用虛擬語氣，表示同時或將來的情況，動詞要用過去式（be動詞用were）或would(could等)+動詞原形，本句話中指的是當時的情況，所以要用過去式，故（A）是正確答案。
21．D． 22．D． 23．C． 24．A． 25．D．
26．（B）had not occurred表示對過去的虛擬，條件句中要用過去完成式，主句中要用should(would, could, might)+動詞原形的過去分詞。
27．（B）had hoped是常見的要求其后的賓語從句用虛擬語氣的句型,虛擬語氣would+動詞原形。
28．（C）表示對過去情況的假設，主句動詞形式為would(should, could, might)+have+過去分詞，條件句為過去完成式，if可以省略，但要把had提前主語前面。（B），（D）的表達不符合英語表達習慣，所以（C）是正確答案。
29．（A）suggest后面的從句要用虛擬語氣形式，其形式為should（可以省略）+動詞原形。
30．A．表示與現在相反的虛擬。
31．A．as though引導的與過去相反的虛擬。
32．D．felt是過去式，所以該句是由as though引導的與過去相反的虛擬。
33．D．as if引導的與現在事實相反的虛擬。
34．A．as if引導的與過去相反的虛擬。
35．C．
36．（D）would rather后接從句要求用虛擬語氣，形式為過去式，表示對現在或將來的假設，或為過去完成式表示對過去的情況的假設。
37．（C）who引導的定語從句中的現在完成時表示動作業已發生，所以主句中表示的虛擬是針對已經發生了的行為，所以應該用過去完成式表示對過去的虛擬。
38．（B）
39．（C）這是一人含蓄虛擬條件句，通過介詞短語without,表示潛在的一種假設，而主句中的情況也早已經發生，所以是對過去情況的一種假設，因此用would not have been achieved這一形式。
40．（D）連so that引導的從句中要求用虛擬語氣，表示一種假設，形式為might+動詞原形。
41．（B）It is time that是一種要求從句用虛擬語氣的常見句型。虛擬語氣形式為動詞的過去式。
42．（C）
43．（C）otherwise用來表示一種含蓄的虛擬假設，因為是對過去(yesterday)的情況的假設，所以應該用would have come形式。
44．（B）所給的四個選項中沒有一個表示對未來的情況的虛擬的形式should+動詞原形，或是were to do，因此可以斷定if引導的條件句在這里最真實的條件句，用一般現在時表示一般將來時，故（B）是正確答案。
45．（A）這是一個混合虛擬語氣的句子，if條件句表示的是對過去情況的假設，而主句是對現在（now）的情況的假設，故用would tell形式。
46．C． 47．C． 48．C．
49．B．would rather引導的虛擬語氣其謂語用過去式。
50．D．would as soon引導的虛擬語氣，其謂語動詞也用過去式.
51．B． 52．B． 53．B． 54．B．
55．C．注意單詞otherwise引導虛擬語氣。
56．C．同上。
57．A．注意詞組for fear that
58．A．注意without
59．C． 60．C． 61．D． 62．B． 64．A． 65．D．