精选优质文档-倾情为你奉上过去完成时一、基础知识1.基本结构:have/has + done 2.否定形式:have/has + not +done. 3.一般疑问句:have或has提前概念: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 )。-|- |-|-那时以前 那时 现在构成: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