2. 助动词have的用法

1)have +过去分词，构成完成时态。例如：

　　 He has left for London.　他已去了伦敦。

　　 By the end of last month, they had finished half of their work.　 上月未为止，他们已经完成工作的一半。

　2)have + been +现在分词，构成完成进行时。例如：

　　　 I have been studying English for ten years. 我一直在学英语，已达十年之久。

　 3)have +been +过去分词，构成完成式被动语态。例如：

　　　 English has been taught in China for many years. 中国教英语已经多年。

1. 助动词be的用法

1) be +现在分词，构成进行时态。例如：

They are having a meeting.　他们正在开会。

English is becoming more and more important. 英语现在越来越重要。

2)　be + 过去分词，构成被动语态。例如：

The window was broken by Tom..　窗户是汤姆打碎的。

English is taught throughout the world.　世界各地都教英语。

3) be + 动词不定式，可表示下列内容：

　　 a. 表示最近、未来的计划或安排。例如：

　　 He is to go to New York next week..　他下周要去纽约。

　　 We are to teach the freshmen.　我们要教新生。

　　 说明： 这种用法也可以说成是一种将来时态表达法。

　　 b. 表示命令。例如：

　　 You are to explain this.　对此你要做出解释。

　　 He is to come to the office this afternoon.　要他今天下午来办公室。

　　 c.　征求意见。例如：

　　 How am I to answer him?　我该怎样答复他？

　　 Who is to go there?　谁该去那儿呢？

　　 d. 表示相约、商定。例如：

　　 We are to meet at the school gate at seven tomorrow morning.　我们明天早晨7点在校门口集合。

　 助动词是帮助主要动词构成各种时态,语态,语气以及否定或疑问结构的动词.助动词分为时态助动词和结构助动词两种.

1.D　 2.C　 3.C　 4.D　 5.A　 6.C　 7.D　 8.B　 9.A　 10.A　 11.D　 12.C　 13.A　 14.C　 15.A

第5章　 助动词

15. It is ordered that a new bridge ______ over the wide river.

A. should be built　　　　　 B. would built

C. will be built　　　　　　　　　　 D. built

14. _______ today, he would get there by Friday.

A. Would have left　　　　　　　 B. Was he leaving

C. Were he to leave　　　　　　　 D. If he leaves

13. ______ it ______ for your help, I couldn’t have made any progress.

A. Had; not been　　　　　　　　　 B. Should; not been

C. Did; not been　　　　　　　　　 D. Not; been

12. -Did you go swimming last Sunday?

　-No. We would have gone ______ nicer.

A. if the weather was

B. would the weather have been

C. had the weather been

D. should the weather be

11. -Do you think the thief entered through the window?

-No, if he had, I don’t believe, _______ broken the living-room’s window.

A. he would have　　　　　　　　 B. he must have

C. he had　　　　　　　　　　　　　　 D. should he have

10. If he ______ it, he _______ it.

A. had seen; could have believed　　　　　 B. saw; couldn’t believe

C. saw; couldn’t have believed　　　　　　 D. has seen; had believed