过去进行时
构成
was/were + doing + 其他
用法
- 用来设置故事背景
eg：Alice was sitting with her sister by the river ... - 描述一个过去的特定时刻正在发生的事情
eg：I was having dinner with my friends. - 口语中,表示委婉的请求或者提意见
这个用法尤其适用于表示态度的动词。如wonder,hope,think等,表达一种特别委婉的请求
eg：I was wondering if you'd like to lend me your car.
eg：I was hoping if you'd like to lend me your car. - 两个过去同时在持续的动作
eg：While I was studing in my dorm,my roommates were talking loudly with their friends.
一般过去时与过去进行时的配合使用
长动作用过去进行时,短动作用一般过去时
when + 短动作 / 长动作 用一般过去时/过去进行时
while + 长动作 用过去进行时
eg：I was walking past the car when it exploded.
eg：The car exploded while I was walking past it.
