(what your mother said ) is true .主语是括号内容,谓语是is 表语是true.(the person) to （whom you just talked ） is (his father) ,其中whom 代之the person,to 其实是talk 搭配的介词,只是提前了,可以这么来说,换成普通句子既是：(the person you just talk to )is (his father),其实英语和汉语很像的啦!