我不知道你在写什么英语怎样写

I don't know what are you writing about~

I don't understand the things you write.

I do not know what you are writing

I don't know what you're writing about?

如果要加一个“真”，那就在“I”的后面加个“really”

I don't know what are you writing about.

I don't know what you are writing.