8. 用于现在完成时的句型

1)It is the first / second time.... that…结构中的从句部分，用现在完成时。例如：

It is the first time that I have visited the city. 这是我第一次访问这城市。

This is the first time (that) I’ve heard him sing.　这是我第一次听他唱歌。

注意：It was the third time that the boy had been late.

2)This is +形容词最高级+that…结构，that 从句要用现在完成时。例如：

This is the best film that I’ve (ever) seen. 这是我看过的最好的电影。

9.过去完成时

1) 概念：表示过去的过去

----|----------|--------|----> 其构成是had +过去分词构成。

那时以前　 那时　 现在

2) 用法

a. 在told, said, knew, heard, thought等动词后的宾语从句。例如：

She said (that)she had never been to Paris. 她告诉我她曾去过巴黎。

b. 状语从句

在过去不同时间发生的两个动作中，发生在先，用过去完成时;发生在后，用一般过去时。例如：

When the police arrived, the thieves had run away. 警察到达时，小偷们早就跑了。

c. 表示意向的动词，如hope, wish, expect, think, intend, mean, suppose等，用过去完成时表示"原本…，未能…"。例如：

We had hoped that you would come, but you didn’t. 那时我们希望你能来，但是你没有来。

3)　过去完成时的时间状语before, by, until , when, after, once, as soon as。例如：

He said that he had learned some English before. 他说过他以前学过一些英语。

By the time he was twelve, Edison had began to make a living by himself. 到了十二岁那年，爱迪生开始自己谋生。

Tom was disappointed that most of the guests had left when he arrived at the party.

汤姆失望了，因为他到达晚会时，大部分客人已经走了。

10. 用一般过去时代替过去完成时

1)　两个动作如按顺序发生，又不强调先后，或用then，and，but 等连词时，多用一般过去时。例如：

When she saw the mouse，she screamed. 她看到老鼠，就叫了起来。

My aunt gave me a hat and I lost it. 姑妈给了我一顶帽子，我把它丢了。

2 ) 两个动作相继发生，可用一般过去时;如第一个动作需要若干时间完成，用过去完成时。例如：

When I heard the news, I was very excited.

3)　叙述历史事实，可不用过去完成时，而只用一般过去时。例如：

Our teacher told us that Columbus discovered America in 1492.