定语从句又称为关系从句，是最常见的从句之一。每年高考题对之均有考查，下面谈一谈定语从句在教学中几个值得注意的问题，供大家参考。
一、定语从句中关系代词与先行词的一致性
定语从句中关系代词一般应与它所指代的先行词的单复数保持主谓一致。例如：
The students who were here just now are from No,2 Senior Middle School.
但注意下列一组句子：
He is the only one of the students who was here just now.
He is one of the students who were here just now.
如果"one of +复数名词"后跟有定语从句，一般情况下"one of"后的复数名词为先行词，但当one前有the only,the very,just the修饰时，先行词则为one。
二、定语从句与强调结构
It is the place where they lived before.
It is in the place that they lived before.
第一个句子为定语从句，where指代the place,在定语从句中作状语，第二个句子为强调结构，强调in the place,that没有意义，把in the place 放回后面句子，句子意思完整。
Where is it that he found the lost watch?(强调句型，强调疑问副词where)。
Where is the watch that he found yesterday.(定语从句，that指代the watch)
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。
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。
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?
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.
- 考试辅导
