同学你好，该知识点来自沪江网校《零基础直达BEC商务英语高级【开学季专享签约班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学晚上好呀，
定语从句中的who和whom叫做关系代词。其中who在定语从句中充当主语,whom充当宾语。
who指人,在从句中做主语
(1) The boys who are playing football are from Class One.
(2) Yesterday I helped an old man who lost his way.
whom指人,在定语从句中充当宾语,常可省略.
(1) Mr.Liu is the person (whom) you talked about on the bus.
希望能帮助你哦