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。

She said (that) she had never been to Paris.

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。

When the police arrived, the thieves had run away.

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…"

We had hoped that you would come, but you didn’t.

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

He said that he had learned some English before.

By the time he was twelve, Edison had began to make a living by himself.

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

典型例题

The students ___ busily when Miss Brown went to get a book she ___ in the office.

A. had written, leftB，were writing, has left C. had written, had leftD. were writing, had left

答案D. "把书忘在办公室"发生在"去取书"这一过去的动作之前，因此"忘了书"这一动作发生在过去的过去，用过去完成时。句中when表示的是时间的一点，表示在"同学们正忙于……"这一背景下，when所引导的动作发生。因此

前一句应用过去进行时。

注意：had no … when还没等…… 就……

had no sooner… than刚…… 就……

He had no sooner bought the car than he sold it.