吕吉尔

定语从句是英语语法的难点之一，其中非限制性定语从句更令同学们难以把握。笔者从非限制性定语从句与限制性定语从句的区别出发，讨论关于非限制性定语从句的常见易错题目的解答方法。

1. 引导限制性定语从句时，关系代词which可以与that互换；但引导非限制性定语从句时，只能用which。

例1She heard a terrible noise,

______ frightened her.

A. that B. which

C. what D. who

例2She heard a terrible noise

______ frightened her.

A. that B. /

C. what D. who

解析： 例1意为：“她听到一个可怕的声音，这使她感到恐惧。”that不能用于引导非限制性定语从句，故选B。例2意为：“她听到了一个使她恐惧的可怕声音。”引导修饰noise的限制性定语从句可以用which或that来引导,故选A。

2. 先行词为reason时，限制性定语可以用why或for which来引导；非限制性定语从句则只能用for which来引导。

例3I had told them the reason, ______ I didnt attend the meeting.

A. for which B. at which

C. for whom D. why

例4I had told them the reason ______ I didnt attend the meeting.

A. when B. which

C. why D. for that

解析： 例3意为：“我早已把理由告诉他们，于是我没有出席会议。”先行词为reason时，非限制性定语从句应用for which引导，故选A。例4意为：“我已经把为什么没有出席会议的原因告诉他们。”the reason why...是常见搭配，答案为C。

3. 引导限制性定语从句的关系代词在从句中担任宾语时可以被省略；但引导非限制性定语从句的关系代词即使作宾语也不能省略。

例5He was eager to go to the hospital to see his stepmother,______ he loved and respected as his own mother.

A. as B. which

C. / D. whom

解析： 本句意为：“他急于去医院看望他的继母，他像对待亲生母亲一样孝敬她。”关系代词whom引导非限制性定语从句并作宾语，不能被省略，故选D。

4．引导限制性定语从句时并作从句宾语的关系代词whom可以用who来代替；但在非限制性定语从句中，whom就不能用who替换。

例6Do you know Tom, _____ we talked about?

A. which B. that

C. whom D. who

例7The American journalist ______ the announcer mentioned in the news broadcast is said to have been killed by the gangsters. Which of the following is wrong?

A. who B. whom

C. whose D. /

解析： 例6意为：“你认识汤姆吗? 我们谈到过他。”应选C。例7意为：“播音员在新闻广播中提到的那位美国记者据说已遭歹徒杀害。……