1. Unit 4 Grammar and usage

2. 1. Inversion of Conditional Omission of “if” 虚拟条件句的从句部分如果含有 were, should, 或 had, 可将 if 省略，再把 were,should 或 had 移到从句句首，实 行倒装。

3. If they were here now, they could help us. Were they here now, they could help us. If you had come earlier, you would have met him. Had you come earlier, you would have met him. If I should have time, I would call her. Should I have time, I would call her.

4. Exercises I First, change the following sentences into conditionals. Second, invert these conditionals.

5. 1. The boy who went swimming in the No- swimming Zone drowned in the river. If the boy hadn’t gone swimming in the No-swimming Zone, he wouldn’t have drowned in the river. Had the boy not gone swimming in the No-swimming Zone, he wouldn’t have drowned in the river.

6. 2. Billy was badly bitten by mosquitoes because he forgot to use the mosquito net last night. If Billy had remembered to use the mosquito net last night, he would not have been bitten by … Had Billy remembered to use the mosquito net last night, he would not have been bitten by …

7. 3. The mother carelessly put the knife within the baby’s reach, and the baby cut herself while playing it. If the mother had carefully put the knife out of the baby’s reach, the baby wouldn’t have cut herself. Had the mother carefully put the knife out of the baby’s reach, the baby wouldn’t have cut herself.

8. Exercises II Multiple Choices

9. 1. _____the exam, he would have attend a college. A. If he passed B. Had he passed C. Were he passed D. If he should pass B 2. _____ five minutes earlier, you could have seen them off. A. If you should arrive B. If you arrive C. Had you arrived D. Should you arrive C 3. _____it rain tomorrow, we should have to put off the visit to the Science Museum. A. Were B. should C. would D. will B

10. 2. Implied conditionals 1. but for, without, under, with etc. But for electricity, there would be no modern industry. Without your help, we could not have succeeded. Under such circumstances I would probably have done the same.

11. 2. otherwise, but, or I ran all the way to school, otherwise I would have been late. He felt very tired yesterday, or he would have helped you. 3. but that ( 要不是 ) But that he was short of money at the time, he would have come to help us.

12. 4. -ing phrases and to-infinitive You would have laughed to see him jump aside. This same thing, happening in wartime, would amount to disaster. 5. If it were (had been) not for … 要不是 If it were not for peace, we could not be living a happy life today. If it had not been for your advice, I would not have accepted the job.

13. Exercises Make some sentences of implied conditionals

14. 3. Unreal Situations We can use even if, as if, as though and if only to introduce unreal situations.

15. 1. even if I would never go to his home even if I were invited to. 2. If only If only the weather were finer! If only you hadn’t offended him!

16. 3. as if /as though She always talks to me as if she were my sister. He walks slowly as if he had hurt his leg. She looks as if she would cry. 在某些语境中，如果不表示假设意义，就不必用 过去式。 It looks as if it is going to rain. The fish smells as if it has gone bad.

17. Exercises Multiple Choices

18. 1. 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 C 2. The actor is 58 years old. But he acts as if he _______ a young man. A. is B. will be C. am D. were D 3. The clouds are getting darker and darker. It looks as if it _______rain. A. is going to B. will C. was going to D. would A

19. 4. Subjunctive mood in wish-clauses 用于 wish 后面的从句，表示与事实相反的情况，或表示将 来不太可能实现的愿望。 1. wish (that) +s + v-ed (were) I wish I were as young as you. 2. wish (that) +s + had done I wish that I had not met him yesterday. 3. wish that +s + would/ could/might do Isn’t it your wish that you could buy a car like that?

20. I wish 和 I hope 都表示 “ 希望 ” 。但 I hope 并 不表示假设意义，随后的动词形式除表示 婉转口气外很少用过去形式。 I hope you’re coming to our party. We hope you will be very happy.

21. Exercises

22. 1.The picture exhibition bored me to death. I wish I ___________to it. A. hadn’t gone B. haven’t gone C. didn’t go D. could not have gone A 2. How I wish I __________ that! Everybody present was angry with me. A. didn’t go B. hadn’t done C. wouldn’t do D. wasn’t doing B

23. 3. —He is a brave man. —Yes, I wish I _________ his courage. A. Have B. had C. will have D. would have B 4. Tom can take his car apart and put it back together again. I certainly wish he _____ me how. A. teaches B. will teach C. has taught D. would teach D

24. 5. Subjunctive mood in: 1) It’s (high/ above) time that somebody did... 2) A would rather (that) B : 现在 did 过去 had done 将来 did

25. 1) It’s (about/high) time +that should do did 你该走了 。 我们该吃饭了。 It’s high time that you went. It’s high time that you were going. It’s high time that you should go. It’s time that we had dinner It’s time that we should have dinner.

26. 2) would rather that 现在： 过去： 未来： I would rather you paid me now. I would rather you had gone, too. Don’t come. I would rather you came tomorrow. did had done