虛擬語氣知識要點剖析
虛擬語氣表示說話人的愿望、假設、猜測或建議，而不表示客觀存在的事實。虛擬語氣通過謂語動詞的特殊形式來表示。下面分別介紹虛語氣在各種句式中的用法。
（一）虛擬氣用于條件狀語從句
條件狀語從句 主句
與現在事實相反 If+主語+動詞過去式
（be動詞一律用were） 主語+would或should+動詞原形
與過去事實相反 If+主語+動詞過去完成式 主語+would或should+ have+過去分詞
與將來事實相反 A:謂語用動詞過去式
B:謂語用were to+動詞原形
C:謂語用should+動詞原形 主語+would或should+動詞原形
注意：主句中的should通常用于第一人稱，would可用于任何人稱，同時也可根據意思用情態動詞could, might等等代替should, would。
1． 表示與現在事實相反：
If he had time, he would attend the meeting.
If I were you, I should study English.
2． 表示與過去事實相反：
If you had come yesterday, you would have met him.
3． 表示與將來事實相反：
If it were to / should rain tomorrow, the meeting would be put off.
If you came tomorrow, we would have the meeting.
4． 注：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來調整。例如：
If you had followed the doctor’s advice, you would be quite all right now.（從句說的是過去， 主句指的是現在。）
5． 以上句型可以轉換成下列形式：
1） 從句省略if，用倒裝句式“were, had , should +主語”
Should there be a meeting tomorrow, I would come.
Had you been here earlier, you would have seen him.
Were I in school again, I would work harder.
2） 用介詞短語代替條件狀語
But for（要不是） the rain we should have a pleasant journey.
Without air, there would be no living things.
(二)虛擬語氣用于賓語從句
1．“wish+賓語從句”表示不能實現的愿望，漢語可譯為“可惜。。。”、“。。。就好了”、“悔不該。。。”“但愿。。。”等。
表示現在不能實現的愿望，從句的謂語動詞用過去式；表示將來不能實現的愿望，用“would (could)+動詞原形”；表示過去不能實現的愿望，用“had+過去分詞”或“(could) would+ have +過去分詞”。例如：
We wish we had arrived there two hours earlier.
I wish you could go with us .
I wish it were spring all the year round.
2．虛擬語氣在動詞arrange, command, demand, desire, insist, order, propose, request, require, suggest等后面的賓語從句中，用“(should)+動詞原形”
He demanded that we (should) start right away.
The doctor ordered that she (should) have stay in bed for a few days.
We suggested that we (should) have a meeting.
注意：insist作“力言”、“強調”解時，賓語從句不用虛擬語氣。只有當insist作“堅持（應該）”解時，賓語從句才用虛擬語氣。
We insisted that she (should) go with us.
Mike insisted that he had never stolen anything.
（三）虛擬語氣用于表語從句、同位語從句
作advice, idea, order, demand, plan, proposal, suggestion, request等名詞的表語從句和同位語從句，其謂語動詞要用虛擬語氣的結構“(should)+動詞原形”
My idea is that he (should ) do exercises first.
We all agreed to his suggestion that we (should )go to Beijing for sightseeing.
（四）虛擬語氣在以as if ( as though)引導的表語從句或狀語從句中的應用。
如果從句表示與現在事實相反，謂語動詞用一般過去時，表示與過去事實相反，謂語動詞用“had +過去分詞”；表示與將來事實相反，謂語動詞用“would (might , could)+動詞原形”。
It looks as if it might rain.
He speaks English so fluently as if he had studied English in England.
但as if (as though)在后的從句也常用陳述語氣，這是因為從句中的情況往往是可能發生的或可被設想為真實的。
It looks as if our side is going to win.
（五）虛擬語氣用于主語從句
在主語從句中，謂語動詞的虛擬語氣結構用“should+動詞原形”的結構，表示驚奇、不相信、惋惜、理應如此等。
It will be desired (suggested, decided, ordered, requested, proposed, etc.)that she should finish her homework this afternoon.
在上述三種主語從句中，should意為“應該”、“竟然”，可以省去，但不可換用would。主句所用動詞的確時態不限。
注意：這種從句表示的是事實。如果說話人對這種事實表示驚奇，就可用虛擬語氣。反之，如果不表示驚奇，that從句也可用陳述語氣。
It is a pity that you can’t swim.
It is strange that he did not come yesterday.
（六）虛擬語氣用于定語從句
這種從句常用在”It is (high) time (that…)”句型中，定語從句的謂語動詞用過去式，或“should +動詞原形（should不能省略，be用were）”來表示，意為“（現在）該。。。”。
It is high time we were going.
It is ( high) time we left (should leave ).
（七）虛擬語氣用于if only引導的感嘆句中
If only I had taken his advice. 我要是聽他的話就好了。
If only I were a bird! 我如果是一只鳥就好了。
（八）虛擬語氣在If it were not for…中的應用
此結構意為“如果沒有”，表示同現在事實相反的假設。例如
If it were not for the rain, the crops should (would )die
If it had not been for…意為“如果當時沒有。。。”，表示同過去事實相反的假設。
If it had not been for your timely help, I would have failed.
（九）虛擬語氣在would rather 后接從句的應用
I’d rather she hadn’t done that.
（從句用過去完成時指過去）
I’d rather you painted the wall green next time.
（從句用過去時指將來）
I’d rather you paid me now.
（從句用過去時指現在）
（此句中would的可看作是表愿望的實義動詞）
（十）虛擬語氣在簡單句中的應用
1）表示說話人謙虛、客氣、有禮貌，使語氣委婉，常出現在日常會話中。
Would you be kind enough to open the door?
It would be better for you not to stay up too late.
2）用于一些習慣表達法中。
You had better go now.
Would you like a cup of tea?
3） 用“may+動詞原形”，表示“祝愿”、“但愿”。may須置于句首。
May you be happy! /May you succeed!
歷屆高考題自我評估
1. If she had worked harder, she ____.
A. would succeed B. had succeeded C. should succeed D. would have succeeded
2. I wish I _____ you yesterday?
A. seen B. did see C. had seen D. were to see
3. If my lawyer _____here last Saturday, he _____me from going.
A. had been ；would have prevented B. had been; would prevent
C. were; would prevented D. were; would have prevented
4. Without electricity human life _____quite different today.
A. is B. will be C. would have been D. would be
5. If he _____, he _____ that food. Luckily he was sent to the hospital immediately.
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
6. I told Sally how to get here, but perhaps I _____for her.
A. had to write it out B. must have written it out
C. should have written it out D. ought to write it out
7. I didn’t see your sister at the meeting. If she _____, she would have met my brother.
A. has come B. did come C. came D. had come
8. When a pencil is partly in a glass of water, it looks as if it _____.
A. breaks B. has broken C. were broken D. had been broken
9. You didn’t let me drive. If we _____ in turn, you _____ so tired.
A. drove; didn’t get B. drove; wouldn’t get
C. were driving; wouldn’t get D. had driven; wouldn’t have got
10. --- I stayed at a hotel white in New York.
--- Oh, did you? You _____ with Barbara.
A. could have stayed B. could stay C. would stay D. must have stayed
11. _____it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.
A. Were B. Should C. Would D. Will
12. Without the air to hold some of the sun’s heat, the earth at night _____, too cold for us to live.
A. would be freezing cold B. will be freezing coldly
C. would be frozen cold D. Can freeze coldly
13. If only he _____ quietly the doctor instructed, he would not suffer so much now.
A. lies B. lay C. had lain D. should lie
14. If you had _____ your test paper carefully before handing it in, you would have made fewer mistakes.
A. looked up B. thought about C. gone over D. gone round
15. What would have happened _____, as far as the river bank?
A. Bob had walked farther B. if Bob should walk farther
C. had Bob walked farther D. if Bob walked farther
跟蹤練習
1. _____your letter, I would have written back two days ago.
A. If I received B. Should I received C. Had I received D. If I could have received
2. If I _____ you, I would try again.
A. am B. was C. were D. be
3. If you _____ 5 minutes earlier, you _____him.
A. should come; had seen B. came; would see
C. come; will see D. had come; would have seen
4. If you _____ at school, you _____ a college student now.
A. had studied hard; would have been B. should have studied hard; should have been
C. had studied hard; would be D. would study hard; must have been
5. The young man insisted that he _____ nothing wrong and _____free.
A. did; set B. had done; should be set C. do; be set D. had done; must be set
6. Mother suggested that I _____my homework first before watching TV.
A. did B. do C. shall do D. have done
7. My suggestion was that the meeting _____ off untill next week.
A. to put B. be put C. should put D. be putting
8. It is important that we _____ wild animals.
A. will protect B. should protect C. shall protect D. are protecting
9. He is talking so much about America as if he _____ there.
A. had been B. has been C. was D. been
10. It is strange that he _____ interest in much of his research.
A. should have lost B. would lose C. had lost D. will lost
11. _____ today, he would get there by Friday.
A. Would he leave B. Was he leaving C. Were he to leave D. If he leave
12. If it were not for the fact that you _____ ill, I would ask you to do this right now.
A. were B. had been C. are D. be
13. Should it rain, the crops _____.
A. would be saved B. would have been saved C. will be saved D. had been saved
14. He treated me as though _____his own son.
A. I am B. I would be C. I was D. I were
15. He smiled as if he _____ my thought.
A. read B. was reading C. had read D. has read
16. _____, all the students would hear.
A. If the teacher had spoken louder B. If the teacher will speak louder
C. Had the teacher spoken louder D. If the teacher spoke louder
17. If only I _____ my watch!
A. hadn’t lost B. haven’t lost C. didn’t lose D. don’t lose
18. You _____ such a serious mistake if you had followed his advice.
A. may not make B. might have not made
C. shouldn’t have made D. might not have made
19. “Have you ever been to Beijing?”
“No, but I wish I _____.”
A. have B. will C. do D. had
20. “ What will you do during the summer holiday?”
“I don’t know, but It’s high time _____ something.”
A. I’m deciding I’ll decide C. I decided D. I decide
Answers: 歷屆高考評估： 1---5 DCADB 6---10 CDCDA 11---15 BACCC
跟蹤練習： 1---5 CCDCB 6---10 BBBAA 11---15 CCADC 16-20 DADDC