一、误认为关系代词whose只用于修饰人

whose用作疑问代词时，主要用于指人;但用作关系代词时，它既可指人也可指物。如：

It was an island, whose name I have forgotten. 它是一座岛，名字我忘了。

The factory, whose workers are all women, is closed during the holidays. 这家工厂工人都是妇女，在假期中工厂关门了。

二、混淆定语从句与并列句

请看下面两题：

1. He has two children, and both of _____ are abroad.

A. them B. which C. whom D. who

2. He has two children, both of _____ are abroad.

A. them B. which C. whom D. who

第1题选A，第2题选C。由于第1题中用了并列连词and，从而使整个句子为并列句，and后应是一个*的简单句，所以选A不选C;第2题没有并列连词and，both of whom are abroad为非限制性定语从句。另外，请比较下面一题：

He has two children, both of _____ being abroad.

A. them B. which C. whom D. who

此题答案为A，其中的both of them being abroad为*主格结构，用作状语。

请再看一组类似的例子：

1. He wrote a lot of novels, many of _____ translated into foreign languages.

A. it B. them C. which D. that

2. He wrote a lot of novels, many of _____ were translated into foreign languages.

A. it B. them C. which D. that

第1应选B，而不能选C，是因为句中的 translated 是过去分词(非谓语动词)，若选C，则该从句无谓语;第2应选C，因为句中有谓语 were translated。比较下面一例：

He wrote a lot of novels, and many of _____ were translated into foreign languages.

A. it B. them C. which D. that

此题与上面的第2题不同，两句间多了一个并列连词and，说明这是一个并列句，故应选B，则不能选C。

三、混淆关系代词与关系副词

有的同学一看到先行词是表示时间、地点、原因的名词，就认为一定要用关系副词，其实也不一定。在此情况下，还要看关系词在定语从句中是用作什么成分，若是用作状语，则用关系副词，若不是用作状语(如用作主语、宾语等)则不能用关系副词，而用关系代词。比较：

This is the factory where I want to work. 这就是我想工作的工厂。(work为不及物动词where在从句中用作状语)

This is the factory that I want to visit. 这就是我想参观的工厂。(visit为及物动词，that用作visit的宾语)

The reason why he can’t come is that he is ill. 他没来的是因为他病了。(come为不及物动词，why在定语从句中用作状语)

The reason that he put forth is very important. 他提出的理由很重要。(put forth为及物动词，that在定语从句中用作其宾语)

比较下面的考题：

1. This is the room _____ I lived ten years ago.

A. that B. where C. who D. what

2. This is the room _____ I lived in ten years ago.

A. that B. where C. who D. what

3. This is the room _____ I bought ten years ago.

A. that B. where C. who D. what

4. This is the room _____ I visited ten years ago.

A. that B. where C. who D. what

5. This is the room _____ I was born ten years ago.

A. that B. where C. who D. what

第1题选B，因为 live 是不及物动词，它无需接宾语;第2题选A，因为虽然 live 不及物，但live in 却是及物，它应有自己的宾语;第3、4题也应选A，因为 buy 和 visit均为及物动词，它们应有自己的宾语;第5应选B，因为 be born 无需有自己的宾语。

四、误认为逗号后一定是非限制性定语从句

有的同学一看见逗号，就以为一定要选which而不选that，但问题是有时根本就不是定语从句。如：

1. If a book is in English, _____ means slow progress for you.

A. as B. which C. what D. that

2. When I say two hours, _____ includes time for eating.

A. as B. which C. what D. that

以上两题均应选that，而不能选which，因为它们根本不是定语从句。之所以选that，是因为句中已有if和when引导的状语从句，逗号后为主句，that为主句主语。

五、混淆定语从句与状语从句

有些试题，从表面看它是定语从句，而实际上它是状语从句;而有些试题则可能完全相反，即从表面看它是状语从句，而实际上是定语从句。请看下面两道试题：

1. I went upstairs _____ I heard someone crying.

A. where B. when C. that D. which

【分析】答案是B而不是A，when的意思是当……的时候，引导的是时间状语从句。(upstairs为副词，不宜用作先行词)

2. He is ______ a clever boy ______ we all like.

A. such, that B. such, as

C. so, that D. so, as

【分析】答案选B，而不是A。such … that …(如此……以致……)用于引导结果状语从句，其中的that不充当句子成分，而such…as…中的as为关系代词，用以引导定语从句并在定语从句充当句子成分。上句中第二空之所以选as，是因为它用作动词like的宾语。

六、弄错定语从句中谓语动词的数

原则上说，定语从句中谓语动词的单复数应与所修饰先行词的单复数保持一致，否则就会出错。如：

谁那样说都是在说谎。

误：Anyone who say that is lying.

正：Anyone who says that is lying.

不算生病的，我们一共20人。

误：There are 20 of us, not counting those who is sick.

正：There are 20 of us, not counting those who are sick.