1. 基本用法
that:既可以用于指人,也可以用于指物。例如:
The book that I bought yesterday is very interesting.(我昨天买的那本书很有趣。这里 that 指代先行词 the book,指物)
The man that you met just now is my teacher.(你刚才遇到的那个人是我的老师。这里 that 指代先行词 the man,指人)
which:一般只用于指物。例如:
The car which is parked outside is mine.(停在外面的那辆车是我的。这里 which 指代先行词 the car,指物)
2. 特殊用法
先行词是不定代词时:当先行词是all, everything, nothing, something, anything, little, much等不定代词时,通常用that而不用which。例如:
All that glitters is not gold.(闪光的并不都是金子。先行词是all,用that)
先行词被序数词或形容词最高级修饰时:通常用that。例如:
This is the best film that I have ever seen.(这是我看过的最好的电影。先行词被最高级the best修饰,用that)
The first thing that we should do is to find out the cause of the accident.(我们应该做的第一件事是找出事故的原因。先行词被序数词the first修饰,用that)
先行词被 the only, the very, the same, the last 等修饰时:一般用 that。例如:
This is the very book that I have been looking for.(这正是我一直在找的那本书。先行词被the very修饰,用that)
当先行词既有人又有物时:用that。例如:
They are talking about the people and the things that they saw on their holiday.(他们正在谈论他们度假时看到的人和事。先行词既有 people 又有 things,用 that)
在非限定性定语从句中:只能用which,不能用that。非限定性定语从句是对先行词起补充说明作用,与主句之间通常用逗号隔开。例如:
The book, which was bought yesterday, is very interesting.(这本书是昨天买的,它很有趣。这里是非限定性定语从句,用which)
介词后:只能用which,不能用that。例如:
The house in which I used to live has been pulled down.(我过去住的那所房子已经被拆除了。介词in后用which)
定语从句,一个句子跟在一名词或代词(先行词)后进行修饰限定,就叫做定语从句。通俗来讲,从句在整个句子中做定语,这个从句就叫做定语从句。
从句在主句中充当定语成分。被修饰的词叫先行词。定语从句不同于单词作定语的情况,它通常只能放在被修饰的词(即先行词)之后。
定语从句由关系词(关系代词、关系副词)引导,关系代词、关系副词位于定语从句句首。