定语从句一、考点聚焦1、功能：相当于形容词，修饰名词或代词，在句中作定语2、位置：定语从句置于被修饰词之后Those who are willing to attend the party, sign here please.3、先行词：被定语从句修饰的词称为先行词（1）先行词一般是名词和不定代词，如:some-, any-, every-和no与-boy, -thing的合成词；或all、none、any、some、that、those等代词。
数词也可以作先行词，人称代词也同样可作先行词。
（2）先行词与关系词是等量关系。
必须注意两点：①先行词在从句中作主语时，从句谓语动词的数由先行词而定。
This is the place which is worth visiting.②关系词在从句句子中充当了成分，其意思就是先行词的意义，所以在从句中不能重复其意。
There are many places we can visit（them）in China.4、关系词：引导定语从句的都称关系词关系代词：who, whom, which, that, whose, as。
关系副词：when, where, why。
that偶尔也作关系副词。
5、确定关系词的步骤（1）先找关系词，看先行词指的是什么。
（2）看关系词在从句中所充当的成分。
二、关系代词引导的定语从句引导定语从句的关系代词主要有who, whom, whose, which, that等。
它们分别代替前面的先行词，并在定语从句中作主语、宾语或定语。
A．who 指人，在定语从句中作主语。
What was the name of the man who lent you the money借钱给你的那人叫什么名字？（定语从句修饰先行词the man，做主语）He who laughs last laughs best. 谁笑到最后谁笑得最好。
（定语从句修饰先行词he）B．whom 指人，在定语从句中做宾语。
在口语或非正式文体中，whom可省略或可用who来代替，但在介词后面以及在非限制性定语从句中只能用whom。
There are some people (whom/who) we like and others (whom/who) we dislike.有些人我们是喜欢的，有些人则是我们讨厌的。
（定语从句分别修饰先行词people, others）Two men, neither of whom I had ever seen before, came into my office.两个人来到我的办公室，我以前从未见过他们。
（在介词后面不用who）C．whose 通常指人，也可指物，在定语从句中做定语，后面要紧跟被修饰的名词。
There are some people whose faces you can never forget.有些人，他们的脸你永远难以忘怀。
（定语从句修饰先行词people）I saw some trees whose leaves were black because of the polluted air.我看见一些树的树叶由于空气污染而发黑。
（定语从句修饰行词trees）注意：The bike whose brake was damaged has now been repaired.那辆坏了闸的自行车现在已经修好了。
=The bike the brake of which was damaged has now been repaired.=The bike of which the brake was damaged has now been repaired.D．which1．指物，在定语从句中做主语或宾语。
做宾语时常可省略。
English is a language which is easy to learn.英语是一门容易学的语言。
（which在定语从句中作主语，不能省略）The children like cookies (which) my wife makes.孩子们喜欢我夫人做的饼干。
(关系代词which作makes的宾语，可以省略)2．which引导的非限制性定语从句可以修饰前面的整个主句，相当于and this。
Jim passed his driving test, which surprised everybody.吉姆通过了驾驶考试，这使大家都感到惊讶。
（定语从句修饰的是整个主句，而不是the driving test）3．which在非限制性定语从句中有时也可以作定语。
John stayed here for a week, during which time we visited the West Lake together.约翰在这里呆了一星期，在此期间我们一起游了西湖。
It might snow this weekend, in which case we won't go to Beijing.周末可能下雪，在这种情况下，我们就不去北京了。
E．that指人时，相当于who或whom；指物时，相当于which。
在定语从句中作主语或宾语（做宾语时可省略）。
He is the man that lives next door. 他就是住在隔壁的那个人。
（定语从句修饰先行词the man，作主语）The dress (that) Ann bought doesn't fit her very well. 安买的衣服不太合身。
提示：在口语中，that有时还可以作关系副词，相当于when或介词+which结构。
We left the day (that) he arrived.他来的那一天，我们就走了。
（that替when）He doesn't see things the way (that) we see them.他看问题的方法和我们不一样。
（that代替in which）注：1）在定语从句中，当先行词指物时，下列情况的关系词宜用that而不用which（1）先行词被①形容词最高级②序数词③数词几种词修饰或被④only、any、few、little、no、all、one of等修饰时。
（2）先行词为all、much、little、none、few、one、something、anything等不定代词时。
（3）先行词中既有人又有物时。
He was looking pleasantly at te children and parcels that filled his bus.（4）先行词在主句中作表语关系词在从句中作表语时。
The village is no longer the one that was 5 years ago.（5）当主句中含有疑问词which时。
Which are the books that you bought for me ?2）、宜用which而不用that的情况（1）在非限制性定语从句中（2）在关系词前有介词时（3）当先行词本身是that时（4）当关系词离先行词较远时F．as和but, than也可作关系代词，引导定语从句。
1. but可被看作关系代词，引导定语从句，在从句中作主语，意义上相当于who not或that not，即用在否定词或具有否定意义的词后，构成双重否定。
如：There is no mother but loves her children．没有不爱自己孩子的母亲。
2. We often advise him not to drink more wine than is good for his health. 我们经常劝他为了身体健康不要喝过量的酒。
3．as: as可以在限制性定语从句和非限制性定语从句中作主语或宾语。
①在限制性定语从句中，先行词被such和the same修饰，从句都用as 引导。
Such books as you bought are useful.②在非限定性定语从句中，比较as 与which：A) 相同之处：都可以用来引导非限制性定语从句，指代前面的主句所表达的内容。
which 可做宾语/表语He failed once more in the match, which was a great pity.The earth runs around the sun, as is known by everyone.B) 区别：1）as引导的非限制性定语从句位置较灵活，可以位于主句前面．中间或后面，一般用逗号与主句隔开，但which所引导的非限制性定语从句只能放在主句之后。
例如：1) As we all know, Galileo’s theory of falling objects is right.= Galileo’s theory of falling objects, as we all know, is right= Galileo’s theory of falling objects is right, as we all know.2) He was thrown into prison, which got round throughout our village2.）as有“如”、“正如”、“像”、“正像”的含义，which 没有。
后面的谓语动词多是see, know, expect, say, mention, report等。
三、关系副词引导的定语从句1．关系副词也可以引导定语从句，在从句中分别表示时间．地点或原因。
关系副词when在从句中充当时间状语，where 充当地点状语，why充当原因状语。
1)when 表示时间, 充当时间状语when=on/ in/ of /at…+which2)where指地点= in / at / from / which3)why指原因= for which但注意：1.当先行词是表地点：place ,room, mountain, airport等时间：time, day, year, month, week,等原因：reason 等名词时,并且分别在句中做地点、时间、原因状语时，应用where ,when ,why引导。
但是如果如果表示时间地点原因的名词不做状语，而是做主语，宾语，或者表语时，必须用关系代词that /which 来引导而不是用where等。
I still remember the day that we spent together。
May 1 is the day that I will never forget。