How do I say "who" as in "I have a few friends who are in that class"? Question: How do I say &quot;who&quot; as in &quot;I have a few friends who are in that class&quot;?
Basically, I want to write this sentence, but I can't figure out how to.
This seems fine:

我有一些朋友
I have a few friends
Wǒ yǒu yīxiē péngyǒu
参加那个班
Attend that class
Cānjiā nàgè bān

But I don't understand how to combine them to mean &quot;I have a few friends who are in that class&quot;.
Some guesses:

Just stick them together: 我有一些朋友参加那个班.  Chinese grammar can be flexible, so this might work.
Use a 是...的 grammar construction: 我有一些是参加那个班的朋友.  Seems a bit unnatural to me, but this might just be because we don't often use an adjective-made-from-a-phrase grammar style in English.
We could rewrite the sentence: 在那个班，我有一些朋友参加 meaning &quot;in that class, I have a few friends who attend&quot; (although, we still have the same &quot;who&quot; problem).
Use '的' to make the second phrase an adjective phrase for the object noun(朋友).


我有一些朋友 (I have some friends)
参加那个班 (attend that class)
我有一些(参加那个班的)朋友 = I have some friends (who attend that class)


More example:


我那个哥哥 (That older brother of mine)
踢足球 (play football)
我(踢足球的)那个哥哥 = (That older brother of mine who plays football)