Do you 是一个一般疑问句句型,是对陈述句中的主语进行提问,也就是说,对于下句:

I have a a pen.(我有一支钢笔),如果对该句的主语 I 进行提问,则用Do you 句型,即为:Do you have a pen?

其他还有:Do you know about the new teacher?你了解那个新来的老师吗?

Do you love me as deep as I love you?你爱我有我爱你那么深吗?