Question

定语从句的先行词怎么用

Answer 1

定语从句：定语从句是在复合句中修饰名词或代词的主谓结构的陈述句。
（简单地讲，就是一个句子做定语，这个句子就称为定语从句。）
例如：This is the professor ( who comes from England.)

1. 先行词：就是被定语从句所修饰的词。
2. 关系词：也叫引导词，包括关系代词和关系副词。
关系代词 有 who, whom, which, that, whose
(1) 当先行词是人，并且在定语从句中作主语时，用 who
The expert visited our company is Mr. Smith.
(2) 当先行词是人，并且在定语从句中作宾语时，用 whom
The girl I met in the street looks like Mary.
(3) 当先行词是物，并且在定语从句中作主语或宾语时，用 which
This is a book describes life in the future.
The novel you lent me last week is very interesting.
(4) 当先行词是人或物，并且在定语从句中作主语或宾语时，用 that
This is the dictionary I bought yesterday.
(5) 当先行词是人或物，并且在定语从句中作定语时，用 whose
This is the boy father works abroad.
The room window faces south is mine.
注：当先行词在定语从句中做宾语时，引导词可以省略。

关系副词 有when, where , why
(1) 当先行词在定语从句中作时间状语时，用when
(2) 当先行词在定语从句中作地点状语时，用 where
(3) 当先行词在定语从句中作原因状语时，用 why

例如：1).I will never forget the day we met for the first time?
2). This is the hospital he was born.
3). We don’t know the reason she didn’t attend the meeting.

Answer 2

回答如下：
定语从句所修饰的名词就是先行词。先行词置于定语从句之前，但中间可以插入其他成分。例如：
This is the house which I lived in before.
I know the boy under the tree who is my neighbour.
The film brought the hours back to me when I was taken good care of in that far-away village．