4．误：This is one of the rooms that is free now．

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

　译：这是目前空着的房间之一。

　析：应改is为are，因为one前没有the only之类的限定词，定语从句在意义上修饰的是名词复数the rooms，而不是单数one。

　(三)、误省略了定语从句中作主语的关系代词。如：

3．误：He is the only one of the teachers who know French in our school．

　正：He is the only one of the teachers who knows French in our school．

　译：他是我们学校中唯一懂法语的人。

　析：应改know为knows，因为one前有the only之类限定词，定语从句在意义上修饰的是the only one，是单数，而不是复数名词the teachers。

2．误：Those who has finished may go home．

　正：Those who have finished may go home．

　译：做完了的人现在可以回家。

　析：应改has为have，因为who指those，是复数。

1．误：Anyone who break the law will be punished．

　正：Anyone who breaks the law will be punished．

　译：任何违犯法律的人将被处罚。

　析：应改break为breaks，因为who指anyone，是单数。

2．误：The book that you need it is in the library．

　正：The book that you need is in the library．

　译：你需要的书在图书馆里。

　析：应删去it，因为从句的宾语是关系代词that。

　(二)、把定语从句谓语动词的单、复数弄错。如：

　由于定语从句的结构和用法比较复杂，初学者在使用时往往容易犯一些错误，最常见的有如下七种：

　(一)、在定语从句中加了多余的定语。如：　

1．误：Some of the boys I invited them didn’t come．

　正：Some of the boys I invited didn’t come．

　译：我邀请的男孩中有几个没有来。

　析：应删去them，因为从句的宾语是省略了的whom，who或that。

(六)、定语从句与同位语从句

　定语从句相当于形容词，它对先行词起修饰、描述或限制作用，而同位语从句则相当于名词，它对其前面的词给予说明或作进一步解释，即说明该词所表示的具体内容。例如：

　The news that we heard is not true.(定语从句)

　The news that he won the prize is not true.(同位语从句)

　另：在"have no idea+从句"结构中，其从句都作idea的同位语。例如：

　I have no idea when she will be back.

(五)、定语从句中的先行词

　Is this book the one that you bought yesterday?

　Is this the book that you bought yesterday?

　第一个句子中，this book是主句的主语，the one 是先行词。在第二个句子中this是主句的主语，the book是先行词。一定要避免出现：Is this book that you bought yesterday?

(四)、定语从句与状语从句

　He found the books where he had put.

　He found the books in the place where he had put.

　第一个句子为状语从句，where he had put 作主句He found the books 的地点状语。第二个句子为定语从句，where引导从句修饰the place。

　This is such an interesting book that I'dlike to read it.

　This is such an interesting book as I'd like to read.

　第一个句子为结果状语从句，在结果状语从句中，it指代book,作read的宾语。第二个句子为定语从句，关系代词as指代先行词book的定语从句中read的宾语。

(三)、定语从句与并列结构

　He has two sons,neither of whom looks like him.

　He has two sons,and neither of them looks like him.

　I've got two sisters.Both of them are in Shanghai.

　第一个句子为定语从句，关系代词whom指代two sons,在定语从名中介词of的宾语。第二个句子为并列结构，由并列连词and连接，人称代词them指代two sons。第三个为两个独立的句子，两个句子中间用句号，两句开头的处一个字母都大写。