英語四級考試中，單獨考察的題幾乎沒有，但是語法知識點卻貫穿整張試卷，下面是頻道為大家整理的知識，希望可以為大家?guī)韼椭黄饋韺W(xué)習(xí)一下吧。 　　過去完成時 　　1) 概念：表示過去的過去 　　其構(gòu)成是had 過去分詞構(gòu)成。 　　那時以前 那時現(xiàn)在 　　2) 用法 　　a.在told, said, knew, heard, thought等動詞后的賓語從句。 　　She said (that) she had never been to Paris. 　　b. 狀語從句 　　在過去不同時間發(fā)生的兩個動作中，發(fā)生在先，用過去完成時;發(fā)生在后，用一般過去時。 　　When the police arrived, the thieves had run away. 　　c. 表示意向的動詞，如hope, wish, expect, think, intend, mean, suppose等，用過去完成時表示"原本…，未能…" 　　We had hoped that you would come, but you didn't. 　　3)過去完成時的時間狀語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.

　　典型例題 　　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. "把書忘在辦公室"發(fā)生在"去取書"這一過去的動作之前，因此"忘了書"這一動作發(fā)生在過去的過去，用過去完成時。句中when表示的是時間的一點，表示在"同學(xué)們正忙于……"這一背景下，when所引導(dǎo)的動作發(fā)生。因此 　　前一句應(yīng)用過去進(jìn)行時。 　　注意： 　　had no … when 　　還沒等…… 就…… 　　had no sooner… than 　　剛…… 就……