what time 意为“几点”问的是具体的时间，一般回答要具体到小时。询问钟表所表示的具体时间(钟点)时,只能用what time。 when 用when提问时，回答既可以是具体的时间，也可以是不具体的时间，如：in the morning，last year，in 1998等范围大的时间。当询问事件发生的年份、月份、日期等非钟点性时习惯只能用when。
第2个回答 2016-01-03
what time与 when 都可以表示“什么时候”. 前者所表示的时间比较精确,指“几点钟”,“几时几分”; 后者所表示的时间范围广,有时也可指“几点钟”,“几点几分”,用来代替what time. 例如： "What time(When) does your mother go to work?" “你母亲什么时候去上班?” "She goes to work atseven" “她七点去上班.” "When will he come back?".“他什么时候回来?”“ "He'll come back tomorrow ”他明天回来.” 此外,what time还可以用作名词,作主语或介词宾语. 简单的说： when和what time的区别在于what time问具体的时间,如某一天的几点钟,甚至几分钟,而when问的时间比较笼统.因此在问生日日期时,不要用“what time”这个特殊疑问词而应该用when.本回答被提问者采纳
第3个回答 2016-01-04
what time常用来问钟点，而when除了问钟点外，还可用来问日期，月份，年份等。有时两者可以换用，有的场合不可以。
1.问钟点时，可以换用。 When do you go to school? What time do you go to school?
2.问日期，月份，年份等，只能用when When were you born? I was born on July 2,1972.
3,当问某事在某天的什么具体时间进行，只能用what time What time did you call this afternoon? I called at 4:00 this afternoon.
另注:
when : 一,副词 ad. 1.(用作疑问副词)什么时候,何时 I'd like to know when they'll let him out. When did you last see Margaret? 2.(用作关系副词,引导关系从句)当...时 There were times when I didn't know what to do. 二,连接词 conj. 1.当...时 John got engaged to her when travelling last winter. Don't get excited when you talk. 2.既然,考虑到 How can he get the promotion when his boss dislikes him? 3.虽然,然而 I had only fifteen dollars on me when the book I wanted cost twenty. 4.在那时,然后 三,代词 pron. 1.什么时候,那时 Since when has she taught here? 四,名词 n. 1.(事件发生的)时间[the S]
what time: 什么时间 问具体时间，如几点钟 例: What time is it now? What time is suitable for us to meet?