while前后时态用法主要依据句子的时间关系来决定,具体有以下几种情况。
当while从句的动作与主句的动作同时发生时,一般使用一般过去时。例如:While he was studying, she was cooking dinner.当while从句的动作在主句动作之前完成时,一般使用过去完成时。例如:While I had already finished my work, he arrived.、
1、在主句动作之后
当while从句的动作在主句动作之后发生时,可以使用一般过去时、现在完成时或者一般将来时,取决于具体语境。例如:While I was watching a movie, he has already cleaned the house. 或 While I was watching a movie, he will clean the house.
2、与主句的动作同时发生且持续一段时间
当while从句的动作与主句的动作同时发生且持续一段时间时,可以使用过去进行时或现在进行时。例如:While she was sleeping, I was reading a book.当while从句表示经常性或习惯性动作时,使用一般过去时。
例如:While I lived in Shanghai, I would often go to the park.当while从句转述过去发生的事实或状态时,使用过去完成时。例如:While she told me her story, I had already heard it before.
当while从句表示将来的意义时,可以使用一般将来时。例如:While I am on vacation next week, I will visit my parents.当while从句表示未来的条件时,使用一般现在时。例如:While she is in town, I can ask her for help.