Is he a friend of yours ?

他是你的朋友吗？

《牛津词典》

Is she a friend of yours?

她是你的朋友吗？

《牛津词典》

I believe Paul was a friend of yours.

我相信保罗曾是你的一个朋友。

《柯林斯英汉双解大词典》

If you,or a friend of yours,wants to see this syllabus after the class,and you don't have one, it's on the Classes v2 server.

如果你或你朋友想在课后看看,但你没有多余的，可以在Classes，v2服务器上找到。

耶鲁公开课 - 新约课程节选

Let's pretend that a friend of yours visits on a very cold winter day.

让我们假设你的一个朋友在一个天气非常寒冷的冬日拜访你。

How about 课堂 - SpeakingMax英语口语达人

Even bigger: a friend of yours says something mean or dismissive to you or to another friend.

FORBES: One Thing You Can Do Right Now To Improve Your Life

" Like, say, including a photo of a friend of yours and saying, "So-and-so likes Garnier hair care products.

ENGADGET: Editor's Letter: Looking back

We hear your colleague, John Warner, a friend of yours with the Senate Armed Services Committee, says today that we have to stay the course.

NPR: Sen. John Kerry on Iraq War, Rosa Parks