【英语语法】定语从句

定语从句概念

在复合句中修饰名词或代词的句子叫做定语从句。

一般用定语来修饰名词或是一个名词短语。而当需要表达复杂一点的意思时，简单地用形容词作定语就没有办法了。此时需要借助一个句子来修饰名词，用作名词的定语，对名词进行限定。简单来讲定语从句就是一个用作定语功能的从句。

• Hermione Granger is a smart girl.
• Hermione Granger is a girl who has magic power.
• 上面句中 smart 形容词作定语，下句中 who has magic power 这个句子作定语，修饰 a girl，叫做定语从句

先行词和关系词

对于定语从句，必须要理解先行词和关系词。

• 先行词： 被定语从句所修饰的对象称为先行词。
• 关系词： 重复指代先行词、起到连接主句和从句的作用，并且在定语从句中充当一定成分的连接词称为关系词。

关系词的作用和类别

作用:

• 1.充当代词（重复指代先行词并且在定语从句中充当一定成分)。
• 2.连接主从句。

关系词可分为关系代词和关系副词两种:

• 关系代词主要起代词的作用，在定语从句中充当主语或宾语。包括：who, whom, which, that, whose
• 关系副词主要起着副词的作用，在定语从句中充当状语。包括：when, where, why

关系代词 who 或 whom 的用法

先行词指人的时候，才能用关系代词 who 或 whom

1. 关系词作主语

• The woman who is standing by the classroom is our Spanish teacher.
  在此句中，the woman 是先行词，关系代词 who 引导定语从句，同时代替先行词在从句中担任主语。
• The girl who plays the piano very well is his girlfriend.
  句中先行词是 the girl，关系代词 who 引导定语从句，同时代替先行词在从句中担任主语。

2. 关系词作表语

• He is no longer the man who he used to be.
  在此句中，the man 是先行词，表示 “人”；关系代词 who 引导定语从句，同时代替先行词在从句中担任表语。

3. 关系词作宾语

这里需要稍微强调一下，关系词在定语从句中既可以作动词的宾语，也可以作介词的宾语。

• l can’t remember the man who/whom l gave the key to.
  在此句中，the man 是先行词，关系代词 who 或 whom 引导定语从句，同时代替先行词在从句中担任介词的宾语。
• The little boy who/whom l met is Jason.
  在此句中，the little boy 是先行词，关系代词 who 或 whom 引导定语从句，同时代替先行词在从句中担任动词的宾语。

指代 “人” 的关系代词 who 和 whom 有何不同呢?

1. who 前面不能与介词搭配使用

因为 who 是主格形式，所以在介词后面不能用 who，比如不能用 with who，而要用 with whom。

• The CEO for whom you are waiting is gone. （The CEO whom you are waiting for is gone.）
  the CEO 是先行词，介词后关系代词不能用 who，而要用 whom，作介词 for 的宾语。

2. whom 在定语从句中不能作主语，只能作宾语或表语而 who 可以作主语，也可以代替 whom 作宾语或表语，但不能用在介词后面，因为 whom 是宾格形式，不能作主语

• Where is the student whom/who Professor Snape praised at the meeting? (作宾语二者皆可)
• The old man who lives next door is a veteran of the Second World War. (作主语不能用 whom)
• They lady with whom you were talking last night was Miss Li.

关系代词 whose

whose 表示所有关系，它的作用如同物主代词 my, your, her, his, their 和 our —样，whose 后面必须要接名词，要注意的是 whose 可以指人也可以指物 。"whose + 名词” 在从句中可作主语、动词的宾语或介词的宾语。

1. whose 为 who 的所有格，作 “某人的……” 的意思，它所指代的先行词必须是人，其引导的定语从句修饰它的先行词，同时它本身在从句中作定语。

• This is the little girl whose parents were killed in the great earthquake.
• The teacher wants to talk to the student whose homework hasn’t beenhanded in.

2. whose 可作 which 的所有格，作 “某物的…”的意思，它所指代的先行词必须是物，其引导的定语从句修饰它的先行词，同时它本身在从句中作定语

• The company whose name is Tesla is in the United States.
• We live in a house whose windows open to the south.

3. whose 可修饰定语从句中的主语、宾语、介词宾语等不同成分。

• His grandpa, whose arms were badly hurt, was quickly taken tohospital.(whose 修饰定语从句中的主语 arms)
• We have to make a decision about my cousin, whose story I’ve just told you.(whose 修饰定语从句中的宾语 story)

4.whose 既可引导限制性定语从句，亦可引导非限制性定语从句。

• Mike whose ambition is to become an astronaut, always works hard. (非限制性定语从句)
• Could you pass me the notebook whose cover is brown? (限制性定语从句)

5. 由于 whose 具有兼作 who 和 which 的所有格的双重功能，故在指人时可用 of whom 代替 whose，指物时可用 of which 代替 whose。

• This kind of book is for children whose native language =the native language of whom) is Chinese.
• Billy has written a novel whose name (=the name of which) l’ve completely forgotten.

下列情况中的 whose 和 of whom 或 of which 不可混用

1. 当 of whom 或 of which 同数词或代词 (如 some, many, little 等) 连用表示部分与整体关系时，通常不可用 whose

• There are 45 students in our class, 35 of whom are League members
• Dr.Sue wrote many books for kids, some of which were translated into Chinese.

2. 当 of whom 或 of which 修饰定语从句中的主语，是表示同位关系的代词 both, all 等时，都不能用 whose

• l have two sons, both of whom are soldiers.
• He has some novels, all of which are written in German.

关系代词 which 的用法

关系词 which 的造句结构类似于 who，可以作从句的主语或宾语，区别在于 which 的先行词是 “物”；而 who 的先行词是 “人”。但 which 所指代的先行词比较复杂一些，它除了可以指单个的名词，也可以指代短语甚至从句。

1. 先行词是单个名词

• A computer is a machine which can do many things for us. (先行词是 computer, which 作定语从句主语)

2. 先行词是一个短语

• He likes playing golf, which is a good exercise. (先行词是一个短语 playing golf , which 作定语从句主语)

3. 先行词是一个句子

• Tina was late, which surprised me. (先行词是前面的整个句子，which 作定语从句主语)

关系代词 that 的用法

关系代词 that 既可以指 “人” 也可以指 “物”，因此 that —般可用来
替换 which 或 who。作宾语时常常可省略。

• The foreigners that/who visited our school yesterday are from Canada.
• l like the book (that/which) my uncle gave me.

既然 that 既可以指 “人” 也可以指 “物”，that 与 which 和 who 在用法上有哪些区别呢?

1. 当先行词中同时出现“人”和“物”时，用 that

• The writer and his novels that the article deals with are quite familiar to us. (关系代词 that 在从句中作宾语)

2. 先行词为指 “物” 的 all, little, few, much 和 none 时，用 that

• All that we need to do now is to practice English. (关系代词 that 在从句中作宾语)
• There is not much that can be done. (关系代词 that 在从句中作主语)
• This article contains little that is useful.(关系代词that在从句中作主语)

3. 先行词有最高级或形容词最高级修饰时，用 that

• Tom is the cleverest boy that l have ever known.
• This is the first play that l have seen since l came here.

4. 先行词是不定代词 something, anything, nothing 和 everything 时，一般用 that

• l refuse to accept the blame for something that is someone else’ s fault.
• l would much rather receive a gift that was unique or that l knew myfriend had put some thought into than something that cost a lot of money but that l didn’ t need or want.

5. 先行词被 any, only, all, every, no, some, much, few, little, the only, the one, the very 和 the right 等成分修饰时，用 that

• I’ve read all the books that you lend me.
• There is no difficulty that they can’t overcome.
• The only thing that we should do is to clam down right now.
• The very problem that l want to solve is like this.

6. that 不能用于介词后和非限制性定语从句中

关系副词 when 的用法

一、先行词指时间

when 可以引导限制性和非限制性定语从句，其先行词须是表示时间的名词，如 day, year 或 time 等。

引导限制性定语从句

• Jack will never forget the day when he met Rose.
• As the smallest child of his family, Alex is always longing for the time when he should be able to be independent.

引导非限制性定语从句

• My favorite season is summer, when l can eat lots of watermelon and icecream.
• He will put off the picnic until May 1st, when he won’ t be so busy.

二、关系副词 when 在从句中作时间状语

when 是在定语从句中作时间状语。提醒大家一定要注意，若定语从句中缺少的不是状语，而是主语或宾语，那么即使先行词是表示时间的名词，也不能用 when 而要用 which 或 that 来引导定语从句。用 when 来导定语从句的前提条件是： when 必须在其引导的定语从句中作时间状语。

• I’ll never forget the time which l spent with my family.
• I’ll never forget the day when l started my own busiiness.

在这两句话里，尽管先行词分别是表示时间的名词 time 和 day，但用的关系词是不同的。在上面的句子当中，由于定语从句中的谓语缺少宾语，因此关系词要充当其中的宾语，所以要用 which。

在下面的句子当中，定语从句中不缺主语或宾语，而是缺少时间状语，所以关系词用 when，这里的 when 作时间状语。

关系副词 where 的用法

一、先行词指地点

where 引导定语从句，其先行词一般是表示地点的名词，如 place, house 等等。

• This is the place where l cook my lunch.
• Literature is the place where the past meets the present to contemplate the future.
• Remember that the best relationship is one where your love for each
  other is greater than your need for each other.

二、关系副词 where 在从句中作地点状语

并不是所有表示地点的先行词都得由 where 来引导从句。还是需要看关系词在从句中充当的成分。如果定语从句缺少主语或宾语，则需要用 which 或 that 引导定语从句。

• lt’s one of the few countries where people drive on the left.
• l can’t remember all the places that we visited in Thailand.

在这两句话里，尽管先行词都是表示地点的名词，但用的关系词是不同的。在上面的句子当中，定语从句中不缺主语或宾语，而是缺少地点状语，所以关系词用 where，这里的 where 作地点状语。在下面的句子当中，由于定语从句中的谓语缺少主语，因此关系词要充当其中的主语，所以要用 that

关系副词 why 的用法

关系副词 why 引导限定性定语从句修饰先行词 reason，在定语从句中充当原因状语。

• l don’ t know the reason why he came so late.
• That is the reason why l don’t want to go.
• He didn’ t tell me the reason why he was so upset.

限制性和非非限制性定语从句

在形式上来讲，二者的区别在于：限制性定语从句中，先行词和关系词之间不用逗号隔开，而非限制性定语从句则有逗号隔开。

限制性定语从句

• The town whose population is shrinking locates in Japan.

非限制性定语从句

• My hometown is Beijing, which is the capital of China.

限制性定语从句

限制性定语从句是用来对一个名词提供必要的信息，来说明定语从句所修饰的先行词的身份或者性质，也可用来限制先行词所指的范围。如果去掉限制性定语从句，主句部分的含义很可能因此而变得不明确，意义不完整， 因此不能用逗号将先行词和定语从句分隔开来。

• The man who is sitting by the window is my father.
  本句中使用的定语从句就是一个限制性定语从句。定语从句 who is sitting by the window 限定了先行词所指的范围，是必不可少的信息，因此不能加逗号将其变为非限制性定语从句。

• The house that Jack bought is over there.

• You will never forget the day when you first stepped into this office.

非限制性定语从句

非限制性定语从句是用来对一个名词提供必要的信息，只是对先行词的进一步的解释、补充或说明。如果丢掉非限制性定语从句，主句部分的含义一样很明确，不会引起误解和歧义。 一般来讲，以下两种先行词后用会非限制性定语从句修饰。

一、专有名词

如果定语从句修饰一个专有名词，一般要用逗号分隔先行词与定语从句，也就是要使用非限制性定语从句。因为专有名词本身已经相对完整，不需要限制。用定语从句只是对它进行补充说明。

• Jane’ s brother, who is in Boston now, is coming home next week.
  这里的先行词 Jane’s brother 是一个专有名词，后面的定语从句只是作为非限制性定语从句来提供附加信息，若把从句去掉句意仍然是完整的。

• Hawaii, which consists of eight principal islands, is a favorite vacation destination.

二、类指名词

除了专有名词，表示泛指的普通名词，即表示的一类事物，而非具体的某一个事物时，后面也常用非限制性定语从句。

• An elephant, which is the earth’ s largest land mammal, has few natural enemies other than human beings.
  这里的 an elephant 是泛指，表示 “大象” 这一类动物，而不是具体的某一头，所以用非限制性定语从句。

非限制性与限制性定语从句的差别

一、逗号的差别

有一类句子用限制性定语从句或非限制性定语从句都符合逻辑，但是句子意义会有所差别，因为强调的部分意义不同。
如:

• The food which wasn’ t in the fridge all went bad. 没有放在冰箱里的那些食物坏了
• The food, which wasn’ t in the fridge, all went bad. 食物都坏了，因为没有放到冰箱里。

上面的句子表示有一些食物坏掉了，就是没有放到冰箱里的一部分食物坏掉了；而下面的句子表示食物都坏了，因为没有放在冰箱里。这时的定语从句更多地起到补充说明的作用，说明食物变质的原因是没放到冰箱里。

二、翻译的差别

限制性定语从句多翻译成 “…的”，是定语的形式。非限制性定语从句往往会翻译成类似状语的形式

• l saw the guy whose father is a doctor.
  我见到了那个父亲做医生的人。(限制性定语从句，翻译成定语形式)

• l am wearing the necklace which my grandmother had left me. 我戴着我奶奶留给我的项链。(限制性定语从句，翻译成定语形式)

• The billionaire had another house built, which he didn’ t need at all. 那位亿万富翁又建了一幢房子，尽管他并不需要。(非限制性，翻译成状语形式)

• The people were desperate for work, any work, which could support their family. 人们急于找工作，什么工作都行，只要能养家糊口。(非限制性，翻译成状语形式)

• Lucy didn’t talk to me , which made me really angry. 露西没有和我说话，这让我非常生气。