3. 提出请求。其形式上虽为过去式，但与过去时间毫不相干，回答中一般要用现在式或将来式：

Eg:--Would you help us? -- Yes, I will.

[ex.]--我能参加这个聚会吗？--当然可以！____________

4. 表示"宁愿"的结构：would rather(sooner)\ would just soon-

1） 与现在（或将来）事实相反：would rather(sooner)\ would just soon +S (主语)+did

2） 与过去事实相反：would rather(sooner)\ would just soon +S (主语)+had + done (p.p)

Eg: I'd rather he didn't go now.

[ex.]我真希望你那时不在场：I______ you ____ (be) on the spot.

5. It is (about\ high) time...(that) + S + did \ (should) do 表示"该是......的时候了"-

Eg: It's (high) time (that) we went \ (should) go home.

[ex.] 这个小孩该上学了：________________________________

6. 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】