"你以为你是谁" 的英文翻译是 "Who do you think you are?" 来源是英语中的一句常用语，表示对某人的自以为是的态度的质疑。例如：

You can't just do whatever you want. Who do you think you are?

Don't talk to me like that. Who do you think you are?

I can't believe you said that to the boss. Who do you think you are?