【教师资格证-英语科三-高频考点】
定语从句起了形容词的作用，在句中修饰一个名词或代词。被修饰的词叫做先行词，引导定语从句的词叫关系 词，它的作用：一是放在先行词与定语从句中间起了连接作用；二是在从句中担当一个成分，并与先行词保持数的 一致。
1.关系代词的用法
（1）作主语用 who, which 和 that，如：
a. He is the man who / that lives next door.
b. The train which / that has just left is for Shenzhen.
（2）作宾语用 whom, who, which, that，如：
a. The man (whom / who / that) we have just seen is a famous writer.
b. Where is the book (which / that) I bought last week?
（3）作定语用 whose，如：
a. He is the man whose car was stolen last week.
b. It was a meeting whose importance I did not realize at that time.
注：“whose +名词中心词”这一结构在定语从句中既能作主语（如上 a 句），又能作宾语（如上 b 句）。
whose 的先行词常用来指人，但有时也可以用来指具体事物或抽象概念，这时可以与 of which 结构互换，词序是：“名词+of which”，如：
They came to a house whose back wall had broken down. (= the back wall of which) He’s written a book the name of which I’ve completely forgotten. (= whose name)
（4）作表语只用 that，它既可以指人，也可以指物，但时常省略。如： He is no longer the man that he used to be.
This is no longer the dirty place (that) it used to be.
2.关系副词
（1）关系副词的用法
① when 指时间，在从句中作时间状语，它的先行词通常有： time, day, morning, night, week, year
如：I still remember the time when I first became a college student. Do you know the date when Lincoln was born?
注：when 时常可以省略，特别是在某些句型和某些时间状语中。
如：Each time he came, he did his best to help us.
But help never stopped coming from the day she fell ill.
② where 指地点，在从句中作地点状语，它的先行词通常有： place, spot, street, house, room, city, town, country 等
如：This is the hotel where they are staying. I forget the house where the Smiths lived. 注：where 有时也可以省略。如：
This is the place (where) we met yesterday.
③ why 指原因或理由，它的先行词只有： reason
如：That is the reason why he is leaving so soon. 注：why 时常也可以省略。如：
That is the real reason he quitted.
（2）使用关系副词应注意下列几点：
①三个关系副词在意义上都相当于一定的介词+which 结构： when = on (in, at, during…) + which;
where = in (at, on…) + which; why = for which.
如：I was in Beijing on the day when (=on which) he arrived. The office where (=in which) he works is on the third floor. This is the chief reason why (=for which) we did it.
②当先行词是表时间的 time, day 等和表地点的 place, house 等时，一定要注意分析从句的结构，如果缺少主语或宾语时，关系词应该用 which 或 that，缺少时间状语或地点状语时，才能用 when 或 where，试比较：
I’ll never forget the day when my hometown was liberated.
I’ll never forget the days which/that we spent together last summer. His father works in a factory where radio parts are made.
His father works in a factory which/that makes radio parts.
③ when 和 where 既可以引导限制性定语从句，也可以引导非限制性定语从句。而 why 只能引导限制性定语从句。
3.连接词只用 that 的情况：
（1）先行词为 all, everything, anything, nothing, little, much 等不定代词。
（2）先行词被 all, any, every, each, much, little, no, some, few 等修饰时。
（3）先行词有形容词最高级和序数词修饰时。
（4）先行词既指人又指物时。
（5）先行词被 the only, the very 修饰时。
（6）句中已经用 who 或 which 时，为了避免重复。
4.连接词只用 which/ who/ whom 的情况：
（1）在非限制性定语从句中，只能用 which 指代物，用 who/whom 指人。
（2）在由“介词+关系代词”引导的定语从句中，只能用 which 指物（“介词+ which”一般在定语从句中分别作时间、地点、原因状语，于是“介词+ which”可以分别用 when/where/why 代替），whom 指人。
（3）先行词本身是 that 时，关系词用 which，先行词为 those/one/he 时多用 who。