引导定语从句的关系代词有：that, which, who, whom, whose, as等，关系代词可作主语、宾语、定语等。
1．who, whom, that这些词代替的先行词是表示人的名词或代词，在从句中可作主语、宾语等。
I've made good friends with several of the students in my school who/whom/that I met in the English speech contest last year.
我已与去年在英语演讲比赛中遇到的我校的几个学生结交为好朋友。
2．whose既可指人又可指物，在定语从句中作定语。指物时，“whose＋名词”可用“the＋名词＋of which”或“of which＋the＋名词”来代替。
①Do you know the boy whose handwriting is very beautiful?
你认识那个书法非常漂亮的男孩吗？
②I'd like a room whose window looks out over the sea.
→I'd like a room, the window of which looks out over the sea.
→I'd like a room, of which the window looks out over the sea.
我想要一个窗户面临大海的房间。
