-- Used in “if” clause

语气(Mood)分三种:直陈语气,祈使语气和虚拟语气.

虚拟语气是一种特殊的动词形式，用来表示说话人所说的话并不是事实，而是一种愿望，假设，怀疑，猜测，建议。

“if” 引导的条件句有真实条件句与非真实条件句两种。

1. 真实条件句所表示的假设

1) 不随时间而改变的自然法则和客观真理

2) 可能发生或实现的：if后面的从句用一般现在时，主句用祈使语气或情态动词.

2. 非真实条件句所表示的假设是不可能发生或不大可能实现的：时态共分两种情况。

If引导的从句 主句

A.与现在事实相反 If+主语+动词过去式(be的过去式一律用were) 主语+would+动词原形

B.与将来事实相反 If+主语+动词过去式(be的过去式一律用were) 主语+would+动词原形

C.与过去事实相反 If +主语+ had+动词过去分词 主语+would+have+过去分词

Exercises:

1. 与现在或将来相反

If you … you would …

were Chairman Hu

were Bush

could choose a place for your house

won a lottery of 5 million

your child were addicted to computer games

came across a blackout in a lift

2. 与过去相反

Write conditionals based on the following facts.

1) She didn’t take the medicine, so she felt carsick.

2) Because the sun was in the right direction, the photos came out very well.

3) The shop didn’t pack the goods properly, so they got damaged.

4) The government raised taxes, so they were very unpopular.

5) He wasn’t able to answer all the questions, so he didn’t pass the examination.

6) He didn’t pass the examination, so he didn’t go to the university.

7) We didn’t get there on time, so we found the doors locked in our faces.

8) She didn’t see Curse of the Golden Flower, so she didn’t understand what I said.

3. Multiple choices

1. What will we do if it _____ tomorrow?

A. snow B. would snow C. snows D. will snow

2. You _____ such a serious mistake if you had followed his advice.

A. may not make B. might not make

C. wouldn’t have made D. might have made

3. _____ to see the doctor right away, he might have been alive.

A. If he went B. If he gone C. If he has gone D. If he had gone

4. If you were older, I _____ you to go there yesterday.

A. will allow B. should allow C. would have allowed D. had allowed

5. If we _____ here ten minutes earlier, we _____ the bus.

A. arrived/would catch B. arrived/would have caught

C. had arrived/had caught D. had arrived/would have caught

6. If I _____ more time, I would have gone with him.

A. had B. had had C. have had D. would have

7. Don’t touch the sleeping tiger. If he woke up, he _____ you.

A. would come B. would come at C. would have come D. will come at

8. If it _____ tomorrow, what would we do?

A. rains B. were to rain C. would rain D. rain

9. If he _____ to the teacher attentively, he _____ the answer to the problem.

A. had listened, would have known B. listened, would know

C. listened, would have known D. had listened, would know

10. ---- I thought you would come back tomorrow.

---- I would if I _____ to attend a meeting.

A. don’t have B. didn’t have C. will not have D. would not have

11. If I had hurried, I _____ the train.

A. would catch B. could catch C. would have caught D. had caught

12. If I had known that, I _____ so.

A. wouldn’t do B. wouldn’t have done C. won’t do D. have not done

13. If I _____ you, I wouldn’t call back.

A. be B. am C. was D. were

14. If the doctor had been available, the child _____.

A. would not die B. would not have died C. could not die D. could die

15. You are late. If you _____ a few minutes earlier, you _____ him.

A. came/ would meet B. had come/ would have met

C. come/ will meet D. had come/ would met

16. If you had told me in advance, I _____ him at the airport.

A. would meet B. would had meet

C. would have met D. would have meet

17. If it _____ another ten minutes, the game would have been cancelled.

A. had rained B. would had rained C. have seen D. did see

18. You _____ the train if you _____ a little earlier.

A. could take/ started B. would have taken/ had started

C. could take/ had started D. would have took / started

19. The Bakers arrived last night, if they’d only let us know earlier, _____ at the station.

A. we’d meet them B. we’ll meet them

C. we’d have met them D. we’ve met them

20. If I _____ you, I _____ more attention to English idioms and phrases.

A. was/ shall pay B. am/ will pay

C. would be/ would pay D. were/ would pay

21. We might have failed if you _____ us a helping hand.

A. have not given B. would not give

C. had not given D. did not give

22. If I _____ the money, I would have bought a much bigger car.

A. possessed B. owned C. had D. had had

23. If her husband had not liked the dress _____.

A.she would be delighted B. he would get mad

C. she would have returned it D. she would take it back to the store

24. If I _____ you, I _____ worry.

A. were/ wouldn’t B. was/ wouldn’t C. been/ would have D. be/ would

25. We _____ delighted if the report _____ true.

A. were/ were B. will be/ were C. may be/ were D. were/ would be

Keys:

CCDCD/BBBAB/CBDBB/CABCD/CDCAB