定语从句语法讲解
一、 知识点梳理
充当定语修饰名词或代词的从句称为定语从句。
被定语从句修饰的名词或代词称为先行词。
定语从句一般紧跟在先行词之后，由一定的连接词引导，连接词称为关系代词(which,that,as,whom,who,whose)或关系副词(when,where,why)
1、 限定性定语从句和非限定性定语从句
起对先行词进行限定、区分的作用。若去掉易产生歧义或使主句意义不明确。(此类定语从句前后没有逗号)
【eg】The dress that my mother bought for me is very beautiful. 我妈妈给我买的裙子很漂亮。
⑵非限定性定语从句
与先行词之间的关系比较松散，只对先行词起说明和描述的作用。若省去，剩余部分意义仍然完整，表达清楚。(此类定语从句前后用逗号隔开)
【eg】Your writings , which everyone admires , are very
marvelous.
你的作品人人欣赏，实在是太了不起了。
Shakespeare , whose plays are popular , was a great
writer.
莎士比亚是个伟大的作家，他的剧作很受欢迎。
⑶某些情况下，一个定语从句既可以作限定性定语从句，又可以作为非限定性定语从句，但二者含义有差别。
【eg】There are ten cars here which are made in China.
这里有十辆中国制造的车。 (这里可能还有其他的车) There are ten cars here , which are made in China. 这里有十辆车，它们都是中国制造的。 (这里只有十辆车) ⑷that和why一般不引导非限定性定语从句，其他引导限定性定语从句的关系代词和关系副词都可以引导非限定性定语从句。 ⑴限定性定语从句
【eg】My elder brother , who is an engineer , is working abroad. 我的哥哥在国外工作，他是一个工程师。
Last year , I visited Quanzhou , which is a beautiful city
in Fujian Province.
去年我游览了泉州，它是福建省一个漂亮的`城市。
⑴which和that指物
① which和that引导的限定性定语从句表事物，可以在定语从句中做主语或宾语。当他们在宾语从句中做宾语时，that和which常可以省略。
【eg】We must respect the custom here that has existed for
hundreds of years.
我们必须尊重这里存在了数百年的习俗。 (做主语) This is the book (that / which) I want to buy.
这就是我想买的那本书。 (做buy的宾语) 多数情况下，that和which 可以通用。
② 在下列几种情况下，引导定语从句的关系代词多用that，不用或少用which。
a 先行词前有形容词的最高级、序数词或the only , the very , the last等表绝对意义的词作修饰语。
【eg】This is the oldest tree that exists in the world.
这是世界上现存最老的一棵树。
The only thing ( that ) he is interested in is collecting stamps.
他唯一感兴趣的事就是集邮。
b 先行词为不定代词(anything , nothing , everything)或被little , few , much, any , no等修饰
【eg】All the songs ( that ) he sang are very popular here.
他唱的所有的歌在这儿都很流行。
Everything that should be done has been done..
一切应该做的事情都已经做了。
若先行词是something，定语从句用 that 和 which 都可以。 c 先行词既包括人又包括物
【eg】They talked of people and things ( that ) they remembered
in England.
他们谈起了记忆中在英国的人和事。
d 当句中已有wh–疑问句，有时为了避免重复，用 that 引导定语从句而不用which。
③ 在下列几种情况下，一般使用which引导定语从句而不用that. a 引导非限定性定语从句
【eg】China , which is the third largest country in the world ,
is playing an important part in the world affairs. 中国是世界上第三大国家，它在国际事务中起着重要的作用。 b that和which 在从句中作介词的宾语。
介词可以放在句末也可以提到关系代词前面。
介词放在句末时，关系代词可用that 和which ，也可省略。
介词提前到关系代词前时，只能用which 不能用that ，且which 不可省。
【eg】A bottle opener is a tool ( which / that ) bottles are
opened with.
=A bottle opener is a tool with which bottles are opened. 开瓶器是一种用来开启瓶子的工具。
c 当关系代词后面有插入语。
【eg】I have received the invitation to your wedding which ,
as I have told you , made me very glad.
我已经收到你的婚礼请柬。这个邀请，正如我所告诉你的，使我感到万分荣幸。
d 若先行词是that，则用 which 引导定语从句。(that which的结构通常出现在谚语中)
【eg】That which is evil is soon learned.
坏事易学。
④ 先行词是way时，引导定语从句的关系代词有三种形式:in which / that或不用引导词。
【eg】The way he speaks is unique.
=The way that he speaks is unique.
=The way in which he speaks is unique.
他说话的方式很奇特。
⑵who,whom 和that指人
① who和that在从句中既可做主语又可做宾语
whom 在从句中只可用做宾语。
当who , whom和that在从句中做宾语时，可以省略。
【eg】Do you know the girl who / that is talking with John over
there?
你认识在那边和John说话的那个女孩吗?
The man (who / whom / that ) you have just talked with is our teacher.
刚才和你说话的那个是我们的老师。
② who , whom , that在从句中都可作介词的宾语。
介词可位于句末也可提到关系代词前。
介词位于句末时，关系代词可用who , whom或that，也可省略。 介词提到关系代词前时，只能用whom不能用that和who，并且whom不可省。
(注意与2/⑴/③/b类比)
【eg】The man ( who / whom / that ) you have just talked with
is our teacher.
=The man with whom you have just talked is our teacher. 刚才和你说话的那个人是我们的老师。
⑶ whose指人或指物，充当名词的修饰语，表示所属关系。
“whose+名词”=“名词+ of which”二者意思相同，可互换。
【eg】Look at the house whose windows are round.
=Look at the house the windows of which are round. 看那座窗户是圆形的房子。
⑷ as引导的定语从句
① 先行词有such 或the same 修饰，或者在as/so as 的结构中，都可用as
做关系代词来引导限定性定语从句。
【eg】I want to buy the same pen as you are using.
我想买一支和你用的那支一样的笔。
He used such expressions as he could find in the texts. 他使用在课文中可以找到的那些词语。
当the same修饰先行词时，引导定语从句的关系代词既可以用as也可用that。
区别：that引导的定语从句表示它所表述的事物与先行词是同一个。
as既可以表示“同一个”又可以表示“同类”。
【eg】This is the same book that I have lost.
这就是我丢失的那本书。
This is the same book as I have lost.
这本书和我丢失的那本一模一样。
② as引导非限定性定语从句
as引导非限定性定语从句,修饰的是前面的整个句子。
which 也有这种用法,两者在大部分情况下可互换。
【eg】She has just cried , as / which I could see from her swollen eyes.
她刚刚哭过，我从她红肿的眼睛就可以看出。
As is known to all , China is the third largest country in the world.
众所周知，中国是世界上第三大繁荣国家。
which引导非限定性定语从句和引导的非限定性定语从句的区别： a which从句只能放在句末，而as从句可位于句首、句中、句末。
【eg】Mark Twain , as we all know , is a great writer. 众所周知，马克吐温是一位伟大的作家。
b 当主句是否定句时，as不能用 which 来替换。as从句所修饰的范围并不包括主句的否定意义。
【eg】Spiders are not insects , as many people think. 蜘蛛并非像许多人所想的那样是昆虫。
3、 关系副词when , where , why的使用
关系副词where , when , why在从句中分别做地点状语、时间状语和原因状语。他们经常可以用“介词+ which ”来替代
⑴when可替换为 on / at / in / during + which , 在定语从句中做时间状语。
【eg】I still remember the day when / on which we first met. 我还记得我们初次见面的那一天。
Do you still remember the summer vacation when / during
which we visited a lot of places in Beijing?
你还记得我们在北京游览了很多地方的那个暑假吗?
⑵ where可替换为 at / in / to + which ，在定语从句中跟在表地点的名词后面做地点状语。
