前者是个完整的问句。后者是个从句,要跟在主句后面。比如Can you tell me who you are.
who are you
单句是"你是谁?"的意思,更加礼貌的问法是“who is that?“
有上下文则要具体分析
例句:Who are you to say?你有什么权利说 ... ?你竟敢说 ... ?(来自知米背单词的信息提供)
who you are
如果没有上下文这样是有语法错误的。
例句:No matter who you are,you can not go in.不管你是谁都不能进来
Who are you.(一般疑问句) 正确!
而 who you are 是用于从句中的,如: I don't know who you are.
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