新概念英语第一册语法：过去完成时

风清扬

　　过去完成时：用法：在过去的时间里，两个动作中，发生在前的哪个动作要用过去完成时。

　　结构：had+过去分词

　　After she had finished her homework, she went shopping.

　　They had sold the car before I asked the price.

　　The train had left before I arrived at the station.

　　After/before引导的时间状语从句放在句首要在句子后面加逗号，如果放在主句后则不用加。

　　1.变疑问句将助动词移到句首

　　Had she finished her homework?

　　2.变否定句在助动词后面加not

　　She hadn’t finished her homework.

　　3.肯定回答及否定回答

　　Yes, she had. No, she hadn’t.

　　4.特殊疑问句：

　　What had she done?