首先要明白“定语从句"指整个从句作定语,起修饰前面的名词或代词(即先行词)的作用,这时此从句就需要关系词例如who来引导,以下为例:
who做主语指充当从句主语,如:
Ishethemanwhowantstoseeyou?其中,who在从句who wantstoseeyou中是动作执行者,做主语,而整个从句修饰先行词theman.woman
who做宾语指充当从句宾语,如:
Heisthemanwho/whomItalkedwithyesterday.其中,who做从句中短语talked with的宾语,而整个从句修饰先行词theman.若介词with 提前,关系代词只能用whom,即Heisthemanwith whomItalkedyesterday.
who做表语指充当从句表语,如:
Sheisnolongerthe womanwhosheusedtobe.此句中who做系动词be的表语.
希望多你有帮助.