问家里多少人

询问对方家里有几口人，可以使用以下句型：

直接询问

How many people are there in your family？

间接询问

You have siblings, right？ Are your parents still healthy？

示例对话

A: How many people are there in your family？

B: There are four people in my family. My mom, dad, sister, and me.

根据这些方法，你可以有效地询问并了解对方家庭的人数。