过去完成进行时是had been doing,怎么不直接用过去进行时,搞那么多这么麻烦?不都表达过去在进行的么?
參考答案: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。
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, left B，were writing, has left C. had written, had left D. 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.
过去进行时
1） 概念：表示过去某时正在进行的状态或动作。
2） 过去进行时的主要用法是描述一件事发生的背景；一个长动作发生的时候，另一个短动作发生。
3) 常用的时间状语
this morning, the whole morning, all day yesterday, from nine to ten last evening, when, while
My brother fell while he was riding his bicycle and hurt himself.
It was raining when they left the station.
When I got to the top of the mountain, the sun was shining.
典型例题
1) Mary ___ a dress when she cut her finger.
A. made B. is making C. was making D. makes
答案C. 割伤手指是已发生的事情，应用过去时。同 时，when表时间的同时性，"玛丽在做衣服时"提供事情发生的背景，因此用过去进行时。
2) As she ___ the newspaper, Granny ___ asleep.
read； was falling B. was reading； fell C. was reading； was falling D. read；fell
答案B.句中的as = when, while，意为"当……之时"。描述一件事发生的背景时，用过去进行；一个长动作发生的时候，另一个短动作发生。句意为 "在她看报纸时，奶奶睡着了。"句中的 fell (fall的过去时)，是系动词，后跟形容词，如：fall sick。
