while引导的从句并不是某种时态的标志；
while可以引导时间状语从句，经常用于一般过去时，过去进行时，现在进行时，一般现在时；一般将来时都有可能
while还可以引导条件状语从句，时态也比较多。
例子：
Who will present his show while he's away? 他不在时，将由谁主持播放他的节目?
How did he make out while his mother was away? 他母亲外出不在时他是怎样过日子的?
While he was speaking, he went like this. 当他讲话时，他像这样做手势。
While the news, so far, has been good, there may be days ahead when it is bad.虽然到目前为止都是好消息，但是可能过几天就有坏消息了。