一，一般过去时
概念：过去某个时间里发生的动作或状态；过去习惯性、经常性的动作、行为；
时间状语：ago,yesterday,the day before yesterday,last week,last(year,night,month…),具体时间,just now,at the age of ,one day,long ago,once upon a time(很久以前),etc.
基本结构：be动词；行为动词的过去式
例句：She often came to help us in those days.
I didn't know you were so busy.
二，过去完成时：
1） 概念：表示过去的过去 ，其构成是had +过去分词构成。
2） 用法
a. 在told, said, knew, heard, thought等动词后的宾语从句。
如： She said (that) she had never been to Paris.
b. 状语从句 在过去不同时间发生的两个动作中，发生在先，用过去完成时；发生在后，用一般过去时。 如：When the police arrived, the thieves had run away.
c. 表示意向的动词，如hope, wish, expect, think, intend, mean, suppose等，用过去完成时表示"原本…，未能…"
如：We had hoped that you would come, but you didn't.
3) 过去完成时的时间状语before, by, until , when, after, once, as soon as。
