一、“介词+关系代词”的用法
当关系代词在定语从句中作介词宾语时，我们通常用“介词+关系代词”引导定语从句。如果指“人”，用“介词+whom”;如果指“物”，用“介词+which”。例如：
Do you know the lady with whom our manager is talking in the office?
Where is the supermarket in which you bought the laptop last week?
使用“介词+关系代词”要注意以下几点：
(一)选用介词的依据：
(1) 根据定语从句中谓语动词的'搭配习惯(即固定短语)。例如：
Yesterday we visited the West Lake for which Hangzhou is famous.
(2) 根据先行词的搭配习惯(约定俗成，不一定是短语)。例如：
The old woman with whom you talked just now is a famous artist.
(3) 根据句子的意思来选择。例如：
The naughty boy made a hole in the wall through which he could see what is happening outside.
(4) 表示“所有”关系或“整体中的一部分”时，通常用介词of。例如：
I have about 20 books, half of which were written by Bing Xin, the famous writer.
(二)在定语从句中，含介词的短语动词不可拆开使用(短语拆开后含义发生变化)，如look after, look for等。例如：
The babies whom the nurses are looking after are very healthy.(正)
The babies after whom the nurses are looking are very healthy.(误)
(三)“of which / whom”有时可以用“whose+名词”结构来改写。例如：
The building whose roof was damaged in the earthquake has been repaired.
=The building of which the roof was damaged in the earthquake has been repaired.
(四)当先行词为way并且定语从句中缺少状语时，通常用in which或that引导定语从句(in which或that可省略);如果定语从句中不缺少状语，则用关系代词引导(that 或which 可省略)。例如：
All of us disliked the way(in which / that)Tom settled the maths problem.
I don’t understand the way(that/which)the teacher explained to me.
(五)in that不可以引导定语从句，但可以引导原因状语从句。例如：
She didn’t attend the meeting in that / because she was seriously ill.
二、“介词+关系代词”与关系副词的转化
(1)当先行词表示地点，定语从句中缺少地点状语时，通常用关系副词where引导，此时也可选用表示地点的介词+which来代替关系副词where。例如：
I visited the village where many children couldn’t go to school because of poverty.
=I visited the village in which many children couldn’t go to school because of poverty.
(2) 当先行词表示时间，定语从句中缺少时间状语时，通常用关系副词when引导，此时也可选用表示时间的介词+which来代替关系副词when。例如：
We’d better fix a date when we will practice speaking English next week.
=We’d better fix a date on which we will practice speaking English next week.
(3) 当先行词为reason，定语从句中缺少表示原因状语时，通常用关系副词why引导，此时也可以用for which来代替关系副词why。例如：
Can you tell me the reason why you were late for school?
=Can you tell me the reason for which you were late for school?下载本文
