英语六级语法知识过去完成时

　　在英语六级考试中，单独考察语法的题型几乎是没有的，但是语法知识点却贯穿整张试卷，下面小编为大家整理了英语六级基础语法知识，希望对大家有所帮助。
　　英语知识：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。
　　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.