when 和 what time 有什么区别?

when:
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.
what time:
conj.何时
例句与用法:
1.Do you know what time it is?
你知道现在都几点吗?
2.I won't tell you what time to leave,you're old enough to use your own discretion.
我不告诉你什么时候离开,你已经长大了,该自己作出决定.
3.What time does your husband return from work?
你丈夫什么时候下班回家?
4.What time is suitable for us to meet?
我们什么时候会面合适?
5.What time are you coming back?
你打算什么时候回来?
6.What time is it now?
现在几点钟?

what time表示的时间比较精确,指"几点钟","几时几分"
when表示的时间比较广,有时也可以指几点钟,与what time互换

when 和 what time 都是问时间的
但when可以表示问哪一天、几点钟等等
而what time只是问几点钟的