高中語法專練：i. 虛擬語氣在條件句中的用法

i. 虛擬語氣在條件句中的用法

1. 虛擬語氣用于if條件句中，主從句的謂語動詞形式參見上表。

If you had come earlier, you would have met him.

如果你來得早一點，你就會遇見他的。

We would go with you, if we had time.

萬一有時間我們就和你一起去。

If it should rain, the crops would be saved.

如果天下雨莊稼就得救了。

2. 虛擬語氣用于錯綜時間條件句中，主從句動作發(fā)生的時間不一致，這時主從句動詞的形式應根據(jù)句意或時間來調整，選用適當?shù)奶摂M形式。

If you had listened to the doctor（過去條件 ）, you would be all right now （現(xiàn)在結果） .

如果當初你聽醫(yī)生的話，現(xiàn)在就全好了。

If the PLA man hadn't saved her（過去條件 ）, she would have died.（過去的結果 ）/she wouldn't be studying here now（現(xiàn)在結果 ）.

如果解放軍當初不救她，她早就死掉了/她就不可能現(xiàn)在在這里學習了。

If he studied hard now（現(xiàn)在條件 ）, he would be a college student soon（將來結果 ）.

如果他現(xiàn)在努力學習，不久就會成為大學生的。

If I were you（現(xiàn)在條件 ），I wouldn't have missed the film last night（過去 ）.

如果我是你，昨天夜里我就不會錯過那場電影了。

3. 如果條件句中包含有一個助動詞、情態(tài)動詞、動詞be或have，有時可以把if省略掉，但這時要把助動詞、情態(tài)動詞、動詞be或have放在主語前。

Were I in school again, I would work harder.

如果我再上一次學，就會努力學習。

Had you been here earlier, you would have seen him.

你若早一點到這里，就會見到他的。

Should there be a meeting tomorrow, I would come.

萬一明天有會議，我會來的。

4. 表示 “若不是”之意時，可以用如下兩種句型：

If it weren't for ... = But for ... 若不是（對現(xiàn)在情況的假設）

If it hadn't been for ... = But for ... 當時若不是（對過去情況的假設）

If it weren't for/But for the rain, we would be playing basketball.

若不是有雨的話，我們現(xiàn)在正在打籃球呢。

If it hadn't been for/But for your timely help, I would have failed in the match.

當時若不是你及時幫助，我在比賽中就失敗了。

5. 在含蓄條件句中，可以用有些介詞（with, without, but for）、連詞（or, otherwise, but, however）、不定式短語、名詞短語或陳述句表示虛擬的條件。

Without electricity , human life would be quite different today.

若沒有電，今天人類的生活就會完全不同了。

A silly man would have done that.

笨蛋才會那樣做。

The tree died, but I should have watered it much more.

那棵樹死了，但是我真應該多澆一點水啊。

Five minutes earlier and you could have met her at the station.

再早五分鐘你就可能在車站見到她了。

It would produce bad results to do that. (= If you have done that, ... . )

你若那樣做的話，就有可能產生糟糕的結果。

專項練習

1. Mr. Brown _______ a house if he had enough money.

A. will buy

B. would buy

C. bought

D. has bought

2. But for John, we _______ the match last week.

A. would have lost

B. would lose

C. had lost

D. lost

3. If the child hadn't been so tired, he _______ asleep so quickly.

A. will not have fallen

B. will not fall

C. would not have fallen

D. had not fallen

4. The Smiths _______ a lovely garden if they did some work in it.

A. will have

B. would have

C. have

D. have had

5. If you learned to swim, you _______ safer in the water.

A. will feel

B. felt

C. would feel

D. feel

6. It _______ a good match if it _______

A. would have been; hadn't rained

B. will be; hadn't rained

C. would have been; shouldn't rain

D. will have been; didn't rain

7. If Mother _______ you were coming, she'd have baked some cakes.

A. has known

B. will know

C. had known

D. would know

8. Peter _______ a rich man today if he _______ more careful in the past.

A. is; had been

B. was; were

C. will be; should be

D. would be; had been

9.If I were to do this work, I _______ it in my own way.

A. would do

B. do

C. will do

D. did

10. If the plane crashed, we _______

A. would all kill

B. will all be killed

C. would all have been killed

D. would all be killed

11. _______ more carefully, she wouldn't have made so many mistakes.

A. If she listened

B. If she listens

C. If she has listened

D. Had she listened

12. If he had taken my advice, he _______ a scientist now.

A. will be

B. is

C. has been

D. would be

13. _______ , we would have visited the museum then.

A. If it does not rain

B. Should it not rain

C. Had it not rained

D. If it has not rained

14. Should it stop raining, I _______ for a walk.

A. had gone

B. went

C. would have gone

D. would go

15. _______ he try again, he might be successful.

A. Could

B. Might

C. Must

D. Should

16. If the teacher hadn't explained it to me, I _______ the problem so well.

A. would never be understood

B. had never understood

C. would never have understood

D. will never have understood

17. —Why didn't you buy that dictionary?

—I _______ if I had had enough money.

A. would

B. would have

C. have bought

D. had bought

18. If Jane hadn't missed the early train, she _______ on time, but she was late.

A. will arrive

B. would arrive

C. would have arrived

D. had arrived

19. _______ , he would be surprised.

A. Were Tom to see you

B. Were Tom see you

C. If Tom is to see you

D. If Tom has seen you

20. But for your help, I _______ the place.

A. can't find

B. can't have found

C. couldn't have found

D. haven't found

21. _______ I known he needed money so badly, I might have managed to help him.

A. Unless

B. When

C. If

D. Had

22. _______ , I wouldn't do that.

A. If I am in your place

B. Were I in your place

C. If I have been in your place

D. If I am to be in your place

23. _______ , I should paint the room white.

A. If I have been you

B. If I would be you

C. If I will be you

D. If I were you

24. If you were offered a trip to the moon, _______ you _______ it?

A. will; accept

B. are; going to accept

C. do; accept

D. would; accept

25. —Alice, why didn't you come yesterday?

—I _______ , but I had an unexpected visitor.

A. had

B. would

C. was going to

D. did

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