翻译:你几点钟上课?

What time do/will you have classes?
对于表示具体的时间“几点钟”提问，根据英语的习惯，用what time 比when好，因为要体现这个具体时间的概念。如果只是问笼统的什么时候，用when而不是what time.

确信！

What time do(will) you have classes?
When do(will) you have classes?

Your how many o'clock attend class?

What time will you have lesson?

When do you start your classes?

When do you begin the class?