定语从句是中学英语中较难掌握的从句之一，其规则繁杂，难以记忆，因而同学们在运用过程中常常会掉入种种陷阱，现归纳分析最常见的六种情况，供大家参考。

一、关系代词that和which错用

A）虽然that 和which 指物时均可在从句中作主语或宾语，但在以下情况下只用that而不用which：

（1） 当先行词为all，everthing，anything，nothing，little，much 等不定代词时。（something后面的句既可用that也可用which引导）

如：He told us all that he had done.

（2）当先行词被 very，both，the only，all，every，no，any，little，much，some 修饰时。

如：This is the only English – Chinese dictionary that I have.

（3）当先行词被形容词的最高级修饰时。

如：This is the most beautiful city that I have visited.

（4）当先行词被序数词修饰时。

如：This is the last lesson that we have this term.

（5） 当先行词既包括人又包括物时。

如：They talked for hours of things and persons that they rememered at the school.

（6）当主语是以who或which开头的特殊疑问句时。

如：Which is the coat that you like best？

（7）当先行词在定语从句中作表语时，无论先行词是人还是物。

如：China is no loner the country that she was.

B）关系代词指物时只用which不用that 的情况。

（1）关系代词在从句中作介词宾语并且介词提至关系代词前时只用which（当介词在从句句尾时，两者皆可）。

如：This is the question about which we have had so much discussion.=This is the question which/ that we have had so much discussion about.

（2）在非限定性定语从句中必须用which不能用that。

如：They have invited me to visit their country，which is very kind of them.

二、关系代词的漏用

定语从句中关系代词作主语时不能省略。（也可以把定语从句改为现在分词形式作定语）

如：The student who/that is standing there is our monitor.

（=The student standing there is our monitor.）

三、关系代词与关系副词的混淆

A）that/ which和when

先行词是时间名词时，定语从句的引导词用关系代词还是关系副词“when ”取决于该先行词在从句中充当主语/宾语还是时间状语。

如：Do you still remember the day （that/which） we first spent together.（作宾语可以省略）

It was on the next day when the baby was born that the mother died.（作状语）

B）that/which 和where

先行词是地点名词时，定语从句的引导词用关系代词还是关系副词“where”取决于该先行词在从句中充当主语/宾语还是地点状语。

如：I will never forget the school （that/which） we visited last Sunday.（作宾语可以省略）

Plants cant grow in the place where there is no water.（作状语）

C）that/which 和why

先行词是reason 时，定语从句的引导词用关系代词还是关系副词“why”取决与该先行词在从句中充当主语/宾语还是原因状语。

如：Is this the reason （that/which） he gives for being late？ （作宾语可以省略）

There are several reasons why we cant do that.（作狀语）

四、定语从句主谓不一致

当定语从句的先行词是one of …的结构时，先行词为of 后的复数名词或代词，从句谓语动词用复数形式；当先行词是the（only/ very ） one of …的结构时，谓语动词用单数形式。

如：This is one of the rooms that are free now.

Professor Johnson is the only one of the experts who kowns a little Chinese.

五、定语从句重复用词

A）关系词与疑问词重复

若主句以疑问词who/which 开头，为了避免重复，定语从句的引导词要用that代替。

如：Who is the man that shook hands with you just now？

Which is the book that you want to borrow from me？

B）关系词与被替换词重复

如：This is the jacket which I bought it last month.（误）

析：关系代词which 已经在从句中充当宾语，it 是多余的。

如：Is this the museum where Jane has worked there for twenty years ？（误）

析：关系副词 where 已经在从句中充当地点状语，there 多余的。

六、定语从句中介词的选用

“介词+关系代词”结构中的关系代词指人时用whom指物时用which，其余的介词选用要考虑到：1.介词与先行词的搭配关系；2.介词与从句中谓语动词的搭配关系；3.介词与从句中形容词、名词等的搭配关系等。（该结构一般可以与对应的关系副词相互转换）

【作者简介】王曰福，甘肃天祝一中。