你哥哥多大年纪用英文怎么说

"How old is your brother?" is the common way to ask someone's age in Engpsh.

来源：这是一种在英语中常用的询问年龄的方式。

Example:

A: How old is your brother?
B: My brother is 30 years old.

例句：

A: 你哥哥多大年纪？
B: 我哥哥30岁。