关系代词	指代对象	引导从句类型	作用成分	用法举例
that	人或物	限制性定语从句或名词性从句	主语、宾语、表语	The book that I bought yesterday is very interesting. He said that he would come back soon. That is all that I know.
who	人	定语从句或主语从句	主语、定语	The man who lives next door is a doctor. Who broke the window is still a mystery. The teacher who you are looking for has gone to the library.
whom	人	定语从句或宾语从句	宾语、定语	The girl whom I met yesterday is my cousin. Whom did you see at the party? The woman to whom he gave the flowers is his wife.
whose	人或物	定语从句或主语从句	定语、主语	The boy whose bike was stolen is crying. Whose book is this? The house whose roof is red belongs to my uncle.
which	物	定语从句或名词性从句	主语、宾语、定语、表语	The car which he bought last week is very expensive. I don't like the movie which we saw yesterday. This is the pen which I lost yesterday. The fact which surprised me most was that he failed the exam.
as	物	非限制性定语从句	主语、宾语、表语	Such books as you need are in the library. He has as many books as I have. He is not such a fool as he looks.