定语从句which与where

which引导定语从句的时候,在从句中作主语,宾语或是表语，分享了定语从句which与where用法。

一、关系副词与“介词+which”互换的情形

当“介词+ which”在定语从句中作时间、地点和原因状语时，可以用相应的关系副词when, where和why来替换。

　　1. when根据情况可以等于in which, at which, on which等。如：

The day when (=on which) she arrived was Thursday. 她到的那天是星期四。

July and August are the months when (=in which) the weather is hot. 七八月是天气很热的月份。——摘自《英语常用词多用途词典》（金盾出版社）

这种替换有时出现在非限制性定语从句中。如：

We’ll put off the picnic until next week, when (=by then) the weather may be better. 我们将把野餐推迟到下星期，那时天气可能会好一点。——摘自《张道真英语语法》（商务印书馆）

　　2. where根据情况可以等于in which, at which, on which等。如：

This is the hotel where ( =in which / at which) they were staying. 这就是他们当时住的旅店。——摘自《英语常用词多用途词典》（金盾出版社）

Do you remember the place where (=at which) we had lunch? 你记得我们吃午饭的地方吗? ——摘自《英语用法指南》（外研社）

这种替换有时出现在非限制性定语从句中。如：

The Tower of London, where (=in which so many people lost their lives, is now a tourist attraction. 在伦敦塔中曾有许多人丧命，它现在是旅游胜地。——摘自《朗文英语语法》（外研社）

　　3. 关系副词若要换成“介词+which”只能是for which。如：

The reason why (=for which) I came here was to be with my family. 我到这里来的原因是要跟我的家里人在一起。——摘自《英语用法指南》（外研社）

My success in business, the reason why (=for which) he dislikes me, has been due to hard work. 他为我在事业上的成功而不喜欢我，我的成功归功于我努力工作。——摘自《朗文英语语法》（外研社）

但是，反过来，for which并不一定能换成why。如：

The documents for which they were searching have been recovered. 他们找寻的文件已经找到了。（此句中的for which也不能换成why，理由同上句）——摘自《高中英语语法详解》（湖南大学出版社）

二、关系副词与“介词+which”不能互换的情形

　　1. 有些语境需要用特定的介词来明确其关系，此时若换成关系副词，则会导致意思不明确或句意不能通顺。如：

The ladder on which I was standing began to slip. 我脚下的梯子开始向下滑动。（句中的on which不能换成where，否则意思不明确）

This I did at nine o’clock, after which I sat reading the paper. 九点钟时我做这事，之后我坐着看报。（句中的after which不能换成when，否则意思不明确）

　　2. 当“介词+which”后面接有被which修饰的名词时，通常不能用关系副词代替。如：

The programme will continue until 1994 by which time $3million will have been spent.

这个项目将持续到1994年。到那时开支将达到300万美元。（句中的by which time不能换成when或where，因为which后跟有它所修饰的'名词time）——摘自《限定词与数量词》（外文出版社）

We arrived at noon, by which time the demonstration was over. 我们是中午到的，这时游业已结束。（句中的by which time不能换成when或where，因为which后跟有它所修饰的名词time）——摘自《英语常用词多用途词典》（金盾出版社）

　　3. 当“介词+which”并不表示时间、地点或原因时，自然不能换成关系副词。

There are three principal routes by which one can drive to North Wales. 开车到北威尔士，有3条主要路线可走。（句中的by which不能换成when或where，因为这里的by which并不表示时间或地点，介词by在此表示“通过”）——摘自《英语常用词多用途词典》（金盾出版社）

This is a subject about which we might argue for a long while. 这是一个我们可能长时间争论的问题。（句中的about which不能换成when或where，因为这里的about which并不表示时间或地点，介词about在此表示“关于”，所涉及的搭配是argue about）——摘自《张道真英语语法

　　4、在表语从句和状语从句中不能互换

1.在表语从句中

Is this hotel ______ you said we were to stay in your letter？.

A. that B. where C. the one D. in which

此题可改为：This hotel is where you said we were to stay in your letter．实际上是由where引导的表语从句，答案为B项。

2.在状语从句中

We had better put the bottle of dleeping pills__kids can not find it in case they mistake the pills for candies.此句中“where”并非引导定语从句，而是引导地点状语从句，故不能用"in which".

若用"in which",那句子就变成了定语从句，

in which kids can not find...

= in the sleeping pill kids can not find...

句子就无法理解通了。

3.当定语从句带有不定式时，只能用prep.+which

如，I want a pen with which to write.

I live in a house in which to spend my rest life.

不能用 I live in a house where to spend my rest life.