where问的是地点,如：where is your sister?
what问的是“什么”,如:what's this?
how问的是状况,如:how are you?
when问的是时间,如:when?
what time问的也是时间,如:what tine is it now?
who问的是人,如:who's that?
what date问的是日期,如：what date is it today?