新目标英语九年级Unit 12 Life is full of the unexpected知识点讲与练过去完成时1.概念:过去发生或已经完成的动作对现在造成的影响或结果,或从过去已经开始,持续到现在的动作或状态。2.时间状语:recently, lately, since…for…,in the past few years, etc. 3.基本结构:have/has + done 4.否定形式:have/has + not +done. 5.一般疑问句: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 通用各种人称。 They had already had breakfast before they arrived at the hote l. 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 一般说来,各种时态都有特定的时间状语。与过去完成时连用的时间状语有: ( 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. 2. 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,且从句的动作先主句的动作时,从句要用过去完成时。 |