4. If only 表示"要是......"---试着总结：

1） 与现在事实相反：If only + ___________(动词的形式？)

2） 与过去事实相反：If only + ___________(动词的形式？)

3） 与将来事实相反：If only +would \ could + do

Eg: If only he were \ had been here!

If only she could marry me!

[ex.]要是上周不那么忙该多好啊！_______I ______(be) so busy last week!

7. 表示"万一、以免、以防"等-in case\ for fear that\ lest+ S + should (\might)+ do

Eg: I'll be silent for fear that I (should\ might) disturb you.

[ex.] 她把戒指藏了起来以防被偷：________________________________________________

8. 就好像是：as if\ as though

1) 主句 + as if\ as though + S + were\ was\ did---表示主句动作和从句动作同时发生：

2) 主句 + as if\ as though + S +would\could + do---表示从句动作可能在将来发生：

3) 主句 + as if\ as though + S +had done---表示从句动作可能在主句动作之前发生：

Eg： She talks as if she knew all about it.

He talks about it again and again as if she would never end.

He behaved as if nothing had happened.

【其他了解知识】

A． 动词be\ intend\ mean\ plan\want\ hope等的过去式，后接动词不定式完成式（即：eg: mean-meant to have done），表示过去想做而没有做的事情；而动词be\ intend\ mean\ plan\want\ hope等的完成式，后接动词不定式（即：eg: mean-have meant to do）,也表示过去想做而没有做的事。

Eg: I intended to have attended the meeting, but I was ill.

= I have intended to attend the meeting, but I was ill.

B. even if\ even though 引导让步状语从句，若要表示与现在情况相反，从句要接"(may\ might) + do"; 若要表示与过去情况相反，从句要接"had done"; 类似的词还有：though\ as though \ so long as \ no matter what \ whatever \ whoever, etc.

Eg: However dangerous it might be, he would have a try.

Even though I had been busy then, I would have helped you.

C. live 用在"long live"中-Long live the people! (人民万岁！)

D. may 用在句子开头表示"祝愿"-May you succeed.\ May you be happy.!

【知识反馈】完成下列习题和练习册中对应的习题。　

1.The two students talked as if they _____ friends for years.

A. should be　B. would be C. have been　　D. had been

2.It is important that I _____ with Mr. Williams immediately.

A. speak　　　 B. spoke C. will speak　　D. to speak

3.Let's say you could go there again, how _____ feel?

A. will you　 B. should you C. would you　D. do you

4.I can't stand him. He always talks as though he____

everything.

A. knew 　B. knows C. has known　　D. had known

5._____ the fog, we should have reached our school.

A. Because of　 B. In spite of C. In case of　　D. But for

6.I would have told him the answer had it been possible, but I _____ so busy then.