when 和while 的区别??越详细越好.

when: [ (h)wen ]

conj. 当...时
pron.&ad. 什么时候

例句与用法:
1. When did that happen?
那件事是什么时候发生的？

2. Turn off the switch when anything goes wrong with the machine.
如果机器出故障，就把开关关掉。

3. He was fond of drawing when he was a child.
他还是个孩子时就喜欢画画。

4. It was raining when we arrived.
我们到的时候正在下雨。

5. It was the sort of morning when everything goes wrong.
那天上午就是那样，事事不顺心。

6. How can they learn anything when they spend all their spare time watching television?
他们把所有的空闲时间都用来看电视了，还能学什麽东西呢？

7. The Queen's last visit was in May, when she opened the new hospital.
女王上次来访是在五月份，她那时主持了这座医院的落成典礼。

while: [ (h)wail ]

conj. 当...的时候
n.&a. 一会儿
v. 消磨

词形变化:
动词过去式:whiled 过去分词:whiled 现在分词:whiling 第三人称单数:whiles

例句与用法:
1. I haven't seen him for a long while.
我已经很久没见到他了。