when与what time都可以用来询问时间，相当于汉语的"什么时候"，它们有时能相互通用，但在多数情况下却不能通用。它们之间异同点主要有三点：

　　一、询问做某事的具体时间(钟点)时，两者可以互相替换。例如：

　　When / What time do you usually get up?你通常什么时候起床？

　　When / What time does the old man begin to work in the garden?那位老人什么时候开始在花园干活？

　　二、询问钟表所表示的具体时间(钟点)时，只能用what time，而不能用when。例如：

　　Excuse me, what time is it, please?打扰一下，请问几点了？

　　What time is it by your watch?你的表几点了？

　　三、询问事件发生的年份、月份、日期等非钟点性时间时只能用when，而不能用what time。例如：

　　When is your birthday?你的生日是哪一天？

　　When is Teachers' Day?教师节是哪一天？

　　When will you have an English party?你们什么时候举行一次英语晚会？

　　[练习]一、用when或what time填空。

　　1. -_______ do you usually go to bed?

　　-At 9:00 in the evening.

　　2. -_______ don't you go to school?

　　-On Saturdays and Sundays.

　　3. I don't have a watch with me. Do you know

　　_______ it is?

　　4. -_______ do you usually play football?

　　-We usually play football after school.

　　二、对划线部分提问。

　　1. I do my homework after supper.

　　2. We usually have breakfast at 7:00.

　　3. It's 10:30 now.

　　4. She washes the clothes on Saturday morning.

　　Keys：一、1. When / What time 2. When 3. what time 4. When

　　二、1. When do you do your homework?

　　2. What time / When do you usually have breakfast?

　　3. What time is it now?

　　4. When does she wash the clothes?

　　(文/姜经志；英语辅导报初一(人教)版03~04学年第41期；版权归英语辅导报社所有，独家网络合作伙伴新浪教育，未经许可，不得以任何形式进行转载。)