He is not the man that he was before.这是个定语从句,that就指代前面的先行词the man.追问但是为什么不能用who呢?
问题描述：
He is not the man that he was before.
这是个定语从句,that就指代前面的先行词the man.
追问
但是为什么不能用who呢?
答
这个句子中,that是做 was的表语.关系代词做表语,不能用who.