过去完成时一、过去完成时的概念与结构特点 概念:过去完成时表示在过去某一时间或动作之前已经发生或完成了的动作,即“过去的过去( past-in-the-past )”
构成:过去完成时由“助动词 had + 过去分词”构成,其中 had 通用于各种人称
They had already had breakfast before they arrived at the hotel
She had finished writing the composition by 10 :00 this morning
二、过去完成时的判断依据 1
由时间状语来判定 ① by + 过去的时间点
如: I had finished reading the novel by nine o'clock last night
② by the end of + 过去的时间点
如: We had learned over two thousand English words by the end of last term
③ before + 过去的时间点
如: They had planted six hundred trees before last Wednesday
④ by the time +过去式 I had cooked super by the time my mother came back
由“过去的过去”来判定
过去完成时表示“过去的过去”,是指过去某一动作之前已经发生或完成的动作,即动作有先后关系,动作在前的用过去完成时,在后的用一般过去时
这种用法常出现在: ( 1 )宾语从句中 当宾语从句的主句为一般过去时,且从句的动作先于主句的动作时,从句要用过去完成时
在 told, said, knew, heard, thought 等动词后的