新概念英语第一册语法总结：过去完成时过去完成时 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。 变疑问句将助动词移到句首Had she finished her homework? 变否定句在助动词后面加notShe hadnt finished her homework. 肯定回答及否定回答Yes, she had. / No, she hadnt. 特殊疑问句What had she done?
