while的前后時態

當while表示同時的時候，主句和從句的時態是一致的，既可以都是一般現在時，又可以都是一般過去時。可以表示過去同時發生或者現在正在同時發生某事。

while的具體用法

1、“當……時候”，引導時間狀語從句(從句動作必須是延續性的)。

Please don't talk so loud while others are working.

While I was cleaning the window，my finger was seriously cut。

2、“雖然，盡管”相當于although，引導讓步狀語從句(常把while放在句首)。

While she is a top student， she has some shortcomings. While the Internet is bridging the distance between people， it may also be breaking some home or will cause other family problems。

3、“只要，如果”等于as long as，引導條件狀語從句。

There is hope while there is life. While you study hard， your effort will pay off。