查人人中国名人网镇江给排水管理处:while和when的区别
来源：百度文库 编辑：查人人中国名人网 时间：2024/04/29 20:45:36
while可以同时跟进行时.就是 doing+while+doing.
when只能加在强调为重点的那个前面.就是
do+when+doing,明白?
while所引导的从句中的动词只能用延续性的动词和动词ing形式．
而when所引导的从句中的动词既可用延续性的动词和动词ing形式又可用短暂性的动词．
while和when如果都用于时间状语从句中，前者更多用进行时，表示主从句两个动作的同时进行，如：I was doing my homework while mother was preparing supper；而后者更强调在一件事情正在发生或即将发生的时候，另一动作发生。如:I was doing my homework when my father came in. / I was about to go out when the telephone rang.
此外，while可用来表示对比。如：I like football while my sister prefers pop music.
when有时译会“既然”，相当于now that用法。如：When you've already got a new job, why are you still not satisfied?
while 还有“而”的意思。