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后应是一个独立的简单句，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为独立主格结构，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)