while跟过去进行时 when跟过去式或过去进行时
when：当……时候，在……时候；既然
当……时候：谓语动词可以是短暂性或持续性的动词。如：
I arrived at home when the telephone rang.(短暂性动词,电话响那时刻)
He was doing the homewok when I watching TV.(看电视是持续性动作)
既然:Why you choose as a teacher when you don't like children?你既然不喜欢小孩子,为什么要当老师呢?
while:在……期间，当……；而，却
当……：谓语动词必须是持续性的。如：
I was doing the housework while she was cooking.(我做家务时,她在做饭.做饭是可持续动作,所以可以用while,也可以用when)
而:表转折时,不可以用when,如:
I like apple while he likes banana.(用于比较和转折)
温馨提示：答案为网友推荐，仅供参考