what time / 和 when 有何区别

What time 是具体时间
WHEN只是问什么时候

what time:问具体时间.
when:问在什么时候做某事.
低级阶段时可以换用,可得弄清楚它们的基本用法:
What time is it? What's the time? By your watch?这三句都是问"现在几点了?"
When will you go there?你准备何时去那儿?
When did you get up this morning?今天早上你几点起床的?

举几个例子你一看就明白!
What time does the train leave?
强调具体是几点几分.可以与When混用.

When will you graduate?
强调大体上的时间,此处不能用What time.

What是具体的某个时刻，when是指某个时间段