定语从句的所有知识点
1.定语从句谁能总结一下知识点
定语从句：人 物1.主语 who/that which/that2.宾语 who/whom/that/省略 which/that/省略3.定语 whose the n.of which/whose4.表语 that that5.状语 不能用which只能用that:1.先行词本身是不定代词all/everything/anything/nothing/much/few/little/none/the one2.先行词被一些词修饰（序数词，最高级）only/few/any/little/no/all/every/very3.先行词中既有物又有人4.who/which/that开头只能用which不能用that1.在非限定从句，先行词是物2.先行词本身是that3.当关系词前面有介词只能用who不能用that1.先行词是one/ones/anyone/those/I/you/he/they2.先行词是人，后面有较长的修饰词3.there be开头4.在非限定从句，先行词是人5.在介词前置时只能用whomone of n.（复数）+定语从句 定语从句中谓语用复数the only one of n.（复数）+定语从句 定语从句中谓语用第三人称单数区分定语从句和强调句：把it is…that去掉，若句子完整是强调句eg:it is the Suez Canal that separates Asia from Africa.It is/was +被强调部分+that+句子剩余部分若先行词是situation之类的抽象名词，用in which/where先行词是the way 做方式状语，用 in which/that/省略the same …as 表示同一类事物the same …that 表示同一件物品eg:this is the same bike as I lost.This is the same bike that I lost,so I take it home.He has four daughters,none of whom is a pianist as he is.He has four daughters.None of them is a pianist as he is.He has four daughters,and none of them is a pianist as he is.。
2.定语从句知识总结（要全面哦）
定语从句（Attributive Clauses）在句中做定语，修饰一个名词或代词，被修饰的名词，词组或代词即先行词。定语从句通常出现在先行词之后，由关系词（关系代词或关系副词）引出。
1.定语从句：定语从句是由关系代词或关系副词引导的从句，其作用是作定语修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句，一般紧跟在它所修饰的先行词后面。
2.关系词：引导定语从句的关联词称为关系词，关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as等；关系副词有where, when, why等。关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。
注：关系代词有主语.宾语之分。一般whom作为宾语。
4.定语：定语用来限定、修饰名词或代词的，是对名词或代词起修饰、限定作用的词、短语或句子，汉语中常用‘……的’表示。主要由形容词担任。此外，名词，代词，数词，分词，副词，不定式以及介词短语也可以来担任，也可以由一个句子来担任.单词作定语时通常放在它所修饰的词之前，作前置定语。短语和从句作定语时则放在所修饰的词之后，作后置定语。
先行词：被定语从句修饰的名词、代词称为先行词。
关系代词引导的定语从句举例。
关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
1、who, whom, that
这些词代替的先行词是人的名词或代词，在从句中所起作用如下：
(1) Is he the man who/that wants to see you？ 他就是想见你的人吗？（who/that在从句中作主语）
(2) He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。（whom/that在从句中作宾语）
2、Whose 用来指人或物，（只用作定语， 若指物，它还可以同of which互换）
(1) They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。
(2) Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。
3、which, that 它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，例如：
(1) A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that在句中作主语）
(2) The package (which / that) you are carrying is about to come unwrapped. 你拿的包快散了。（which / that在句中作宾语）
请给个好评，谢谢
3.定语从句的所有知识点
定语从句
定语从句是由关系代词或关系副词引导的从句，其作用是作定语修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句，一般紧跟在它所修饰的先行词后面。
关系词
引导定语从句的关联词称为关系词，关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as等，绝对没有WHAT；关系副词有where, when, why等。关系词常有3个作用：
①连接作用，引导定语从句。
②代替主句中的先行词，甚至可能是主句中的一部分或者整个主句。
③在定语从句中充当一句子成分。
注：关系代词有主语、宾语之分。一般whom作为宾语。关系代词在从句中作主语，宾语，表语，定语等，关系副词在从句中作地点状语，时间状语，原因状语等。
定语
定语用来限定、修饰名词或代词的，是对名词或代词起修饰、限定作用的词、短语（动词不定式短语、动名词短语和分词短语）或句子，汉语中常用‘……的’表示。主要由形容词担任，此外，名词，代词，数词，分词，副词，不定式以及介词短语也可以来担任，也可以由一个句子来担任。单词作定语时通常放在它所修饰的词之前，作前置定语。短语和从句作定语时则放在所修饰的词之后，作后置定语。
先行词
被定语从句修饰的名词、代词称为先行词。
编辑本段
关系代词引导的定语从句举例
关系代词所代替的先行词是人或物的名词或代词，并在从句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
who, whom, that
这些词代替的先行词是人的名词或代词，who做主语指人，whom作宾语指人，that既可作主语又可作宾语（作宾语可以省略），可以指人也可以指物。在从句中所起作用如下：
(1) Is he the man who/that wants to see you？ 他就是想见你的人吗？（who/that在从句中作主语）
(2) He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。（whom/that在从句中作宾语）
Whose 用来指人或物
（只用作定语， 若指物，它还可以同of which互换，指人的时候也可以用of whom 代替）
(1) They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。
(2) Please pass me the book whose (of which) color is green. 请递给我那本绿皮的书。
which, that
它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，作宾语时可以省略，例如：
(1) A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that在句中作主语）
(2) The package (which / that) you are carrying is about to come unwrapped. 你拿那个包裹快要散开了。（which / that在句中作宾语）
4、as
as 可以做主语，也可以作宾语，作宾语时可以省略，指人或者物。
不知道你要多少，后面还有很多。
4.关于英语中定语从句的知识点
关系代词引导的定语从句 关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。
关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。 1)who, whom, that 这些词代替的先行词是人的名词或代词，在从句中所起作用如下： Is he the man who/that wants to see you？ 他就是想见你的人吗？（who/that在从句中作主语） He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。
（whom/that在从句中作宾语） 2) Whose 用来指人或物，（只用作定语， 若指物，它还可以同of which互换）， 例如： They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。 Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。
3)which, that 它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，例如： A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that在句中作主语） The package (which / that) you are carrying is about to come unwrapped. 你拿的包快散了。
（which / that在句中作宾语） 关系副词引导的定语从句 关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。 1)when, where, why 关系副词when, where, why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用，例如： There are occasions when (on which) one must yield. 任何人都有不得不屈服的时候。
Beijing is the place where (in which) I was born. 北京是我的出生地。 Is this the reason why (for which) he refused our offer？ 这就是他拒绝我们帮助他的理由吗？ 2)that代替关系副词 that可以用于表示时间、地点、方式、理由的名词后取代when, where, why和"介词+ which"引导的定语从句，在口语中that常被省略，例如： His father died the year (that / when / on which) he was born. 他父亲在他出生那年逝世了。
He is unlikely to find the place (that / where / in which) he lived forty years ago. 他不大可能找到他四十年前居住过的地方。 判断关系代词与关系副词 方法一： 用关系代词，还是关系副词完全取决于从句中的谓语动词。
及物动词后面无宾语，就必须要求用关系代词；而不及物动词则要求用关系副词。例如： This is the mountain village where I stayed last year. I'll never forget the days when I worked together with you. 判断改错（注：先显示题，再显示答案，横线；用不同的颜色表示 出。）
（错） This is the mountain village where I visited last year. （错） I will never forget the days when I spent in the countryside. （对） This is the mountain village (which) I visited last year. （对） I'll never forget the days (which) I spent in the countryside. 习惯上总把表地点或时间的名词与关系副词 where, when联系在一起。此两题错在关系词的误用上。
方法二： 准确判断先行词在定语从句中的成分（主、谓、宾、定、状），也能正确选择出关系代词/关系副词。
5.英语中定语从句的所有知识点
定语从句在句中做定语，修饰一个名词或代词，被修饰的名词词组或代词即先行词。
定语从句通常出现在先行词之后，由关系词（关系代词或关系副词）引出。关系代词有：who, whom, whose, that, which等。
关系副词有：when, where, why等。关系代词引导的定语从句 关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。
关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。1)who, whom, that 这些词代替的先行词是人的名词或代词，在从句中作主语和宾语。
例如： Is he the man who/that wants to see you？ 他就是你想见的人吗？（who/that在从句中作主语） He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。（whom/that在从句中作宾语）2) whose 用来指人或物，（只用作定语， 若指物，它还可以同of which互换）。
例如： They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。 Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。
3)which, that所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等。例如： A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。
（which / that在句中作宾语） The package (which / that)you are carrying is about to come unwrapped. 你拿的包快散了。（which / that在句中作宾语）关系副词引导的定语从句 关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。
1）关系副词when, where, why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用。例如： There are occasions when (on which) one must yield. 任何人都有不得不屈服的时候。
Beijing is the place where(in which) I was born. 北京是我的出生地。 Is this the reason why (for which) he refused our offer？ 这就是他拒绝我们帮助他的理由吗？2)that代替关系副词，可以用于表示时间、地点、方式、理由的名词后取代when, where, why和"介词+ which"引导的定语从句，在口语中that常被省略。
例如： His father died the year (that / when / in which) he was born. 他父亲在他出生那年逝世了。 He is unlikely to find the place (that / where / in which) he lived forty years ago. 他不大可能找到他四十年前居住过的地方。
判断关系代词与关系副词 方法一： 用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要求用关系代词；而不及物动词则要求用关系副词。
例如： This is the mountain village where I stayed last year. 这是我去年呆过的山村。 I'll never forget the days when I worked together with you.我永远不会忘记与你共事的日子。
判断改错： （错） This is the mountain village where I visited last year. （错） I will never forget the days when I spent in the countryside. （对） This is the mountain village (which) I visited last year. （对） I'll never forget the days (which) I spent in the countryside. 习惯上总把表地点或时间的名词与关系副词 where, when联系在一起。此两题错在关系词的误用上。
方法二： 准确判断先行词在定语从句中的成分（主、谓、宾、定、状），也能正确选择出关系代词/关系副词。例1. Is this museum ___ you visited a few days age? A. where B. that C. on which D. the one例2. Is this the museum ____ the exhibition was held. A. where B. that C. on which D. the one答案：例1 D，例2 A例1变为肯定句： This museum is ___ you visited a few days ago.例2变为肯定句： This is the museum ___ the exhibition was held. 在句1中，所缺部分为宾语，而where, that, on which都不能起到宾语的作用，只有the one既做了主句的表语，又可做从句的宾语，可以省略关系代词，所以应选D。
而句2中， 主、谓、宾俱全，从句部分为句子的状语表地点，既可用副词where，又因 in the museum词组，可用介词in + which 引导地点状语。而此题中，介词on 用的不对，所以选A。
关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选择关系代词（who, whom, that, which, whose）； 先行词在从句中做状语时，应选择关系副词 （ where 地点状语，when 时间状语，why 原因状语） 。限制性和非限制性定语从句 1） 定语从句有限制性和非限制性两种。
限制性定语从句是先行词不可缺少的部分，去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明，去掉了也不会影响主句的意思，它与主句之间通常用逗号分开。例如： This is the house which we bought last month. 这是我们上个月买的那幢房子。
（限制性） The house, which we bought last month, is very nice.这幢房子很漂亮，是我们上个月买的。（非限制性）2） 当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的。
例如： Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了，他曾经是我的老师。 My 。
6.求定语从句知识要点
定语从句是主要用来修饰它前面的先行词（名词或代词）的从句，所以又称形容词从句。
根据与先行词的关系，定语从句可分为限制性定语从句和非限制性定语从句。定语从句主要考查引导定语从句的关系代词或关系副词；介词+关系代词以及非限制性定语从句。
具体考点如下： 考点一： 引导定语从句的引导词有关系代词（who, whom, which, that, whose）和关系副词（as, when, where, why）等。但是当下列情况出现时，对引导词有特殊要求。
1.指物只能用 that不用which 的情况 1）.当先行词是不定代词时，如： all, little, much, none, one, everyone, something, anything, everything, nothing 等。 2）.当先行词被the only, the very, the same, little, few, no， 等修饰时。
3）.当先行词被序数词或形容词最高级修饰时。 4）.在疑问词who、which、what开头的句子中。
5）当定语从句为there be 句型时，关系代词只能用that，也可以省略。 This is the fastest train (that) there is to Beijing. 6）.当主句是以which 或 who 开头的特殊疑问句时，关系代词只能用 that。
Who is the girl that is talking with Mr. Brown? 7）.如果出现两个或两个以上的先行词，并同时兼指人和物时，关系代词用that。 We are talking about the people and countries that we have visited. 8）.当先行词在定语从句中做表语时，关系代词只能用that，也可以省略。
如： China is not the country (that) it was. 2.指物只能用which 不用that的情况 1）.在非限制性定语从句中 2）.在介词后面 3.指人时只能用who不用 that的情况 1）.先行词为one, ones或anyone. 2）.先行词为those. 3）.在there be开头的句子中。 Eg: There is a man who called himself Mr. Wu at the gate. 4）. 在非限制性定语从句中。
4.“the same 。as”, “such。
as” 中的as 可以指人或物，作从句的主语、宾语、表语或介词的宾语。如： Such money as he earned was spent on spirits and tobacco. Is this the same mosquito as bit you just now? He was not half such a coward as we took him for. 5.why引导表示原因的定语从句，其先行词一般是reason。
当主句主语是reason时，作主句表语的成分不能有because和because of 。其结构一般为the reason why…is that…，或者 the reason that … is that…，如： He did not tell us the reason why he was late again. The reason why (that)he didn't come is that he was ill. 考点二： 在“介词+which / whom”的结构中，介词的选择取决于三种情况： 1.定语从句中谓语动词或表语的搭配 This is the college in which I am studying. He is the man about whom we are talking. 2.先行词与介词的习惯搭配 当先行词表示“领域、方面”时，如：aspect, respect, area, field等，用 in which； 当先行词表示“价格、利率、速度”时，如：rate, price, speed 等，用at which； 当先行词表示“程度”时，如：degree, extent等，用 to which； 当先行词表示“根据、依据、基础”时，如：grounds, foundation, basis等，用 on which; The speed at which the machine operates is shown on the meter. 仪表上显示出这台机器的运转的速度。
It is useful to be able to predict the extent to which a price change will affect supply and demand. 3.当定语从句为最高级时只能用of which，否则用其他介词 I have five dictionaries of which Longman Dictionary is the best. I have five dictionaries among which Longman Dictionary is published in UK. 注意：不可拆分的动词短语介词不能提前，如put up with；有的短语可能有不同的介词搭配，此时需要根据上下文来确定。如：be familiar with / to ; compare with / to。
考点三： 当先行词为表示时间的名词（如：time, day, year, week, month, occasion）或地点的名词（如：place, room, city, country）时，一般用关系副词 when 或 where. 分别相当于in which, at which, on which。但是当这些表示时间或地点的名词作从句的宾语时，则要用关系代词that 或which。
I can't forget the days when (in which) I lived with you. Can you tell me the day when (on which) the first satellite was sent into space? China is the only country where (in which) wild pandas can be found. I'll never forget the village where I spent my childhood. I will never forget the days that (which) I spent in Beijing University. （本句days 作spend 的宾语，故用关系代词that / which ） I have never been to Beijing, but it's the place that I most want to visit.（本句place 作visit 的宾语。） 考点四： 非限定性定语从句不能用that引导， 一般用引导词which / as或who（指人），非限定性定语从句既可以修饰主句的部分内容，也可修饰主句的全部内容。
as引导的非限定性定语从句既可以放在主句之前，也可以放在主句之后，但which或who引导的非限定性定语从句不能放在主句句首。 As we all know, the moon is a satellite of the earth. The large area is covered with thick snow, which affects people's life greatly. His speech, which bored us to death, was over at last. Her sister, who lived in another city, was coming to visit her. 关于非限制性定语。
7.定语从句的相关知识点
定语从句知识点很多的 ~\（≧▽≦）/~ 给你一些用的多的吧~~~
定语从句
定语从句是由关系代词或关系副词引导的从句，其作用是作定语修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句，一般紧跟在它所修饰的先行词后面。
关系词
引导定语从句的关联词称为关系词，关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as等，绝对没有WHAT；关系副词有where, when, why等。关系词常有3个作用：
①连接作用，引导定语从句。
②代替主句中的先行词，甚至可能是主句中的一部分或者整个主句。
③在定语从句中充当一句子成分。
注：关系代词有主语、宾语之分。一般whom作为宾语。关系代词在从句中作主语，宾语，表语，定语等，关系副词在从句中作地点状语，时间状语，原因状语等。
定语
定语用来限定、修饰名词或代词的，是对名词或代词起修饰、限定作用的词、短语（动词不定式短语、动名词短语和分词短语）或句子，汉语中常用‘……的’表示。主要由形容词担任，此外，名词，代词，数词，分词，副词，不定式以及介词短语也可以来担任，也可以由一个句子来担任。单词作定语时通常放在它所修饰的词之前，作前置定语。短语和从句作定语时则放在所修饰的词之后，作后置定语。
先行词
被定语从句修饰的名词、代词称为先行词。
编辑本段
关系代词引导的定语从句举例
关系代词所代替的先行词是人或物的名词或代词，并在从句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
who, whom, that
这些词代替的先行词是人的名词或代词，who做主语指人，whom作宾语指人，that既可作主语又可作宾语（作宾语可以省略），可以指人也可以指物。在从句中所起作用如下：
(1) Is he the man who/that wants to see you？ 他就是想见你的人吗？（who/that在从句中作主语）
(2) He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。（whom/that在从句中作宾语）
Whose 用来指人或物
（只用作定语， 若指物，它还可以同of which互换，指人的时候也可以用of whom 代替）
(1) They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。
(2) Please pass me the book whose (of which) color is green. 请递给我那本绿皮的书。
which, that
它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，作宾语时可以省略，例如：
(1) A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that在句中作主语）
(2) The package (which / that) you are carrying is about to come unwrapped. 你拿那个包裹快要散开了。（which / that在句中作宾语）
4、as
as 可以做主语，也可以作宾语，作宾语时可以省略，指人或者物。
8.定语从句高考知识点
介词+关系词1）介词后面的关系词不能省略。
2)that前不能有介词。3） 某些在从句中充当时间，地点或原因状语的“介词+关系词”结构可以同关系副词when 和where 互换。
This is the house in which I lived two years ago.This is the house where I lived two years ago.Do you remember the day on which you joined our club?Do you remember the day when you joined our club？先行词和关系词二合一1)Whoever spits in public will be punished here.(Whoever 可以用 anyone who 代替)2)The parents will use what they have to send their son to technical school.(what 可以用all that代替)as, which 非限定性定语从句由as, which 引导的非限定性定语从句，as和which可代整个主句，相当于and this或and that。As一般放在句首，which在句中。
As we know, smoking is harmful to one's health.The sun heats the earth, which is very important to us.典型例题1)Alice received an invitation from her boss, ___came as a surprise.A. it B. that C. which D. he答案C. 此为非限定性从句，不能用 that修饰，而用which.,it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。况且选he句意不通。
2)The weather turned out to be very good, ___ was more than we could expect.A. what B. which C. that D. it答案B。which可代替句子，用于非限定性定语从句，而what不可。
That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。3)It rained hard yesterday, ____ prevented me from going to the park..A. that B. which C. as D. it答案B.as 和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。
但不同之处主要有两点：（1） as 引导的定语从句可置于句首，而which不可。（2） as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。
在本题中，prevent由于是行为动词，所以正确选项应为B。As 的用法例1. the same… as;such…as 中的as 是一种固定结构， 和……一样……。
I have got into the same trouble as he (has).例2. as可引导非限制性从句，常带有'正如'。As we know, smoking is harmful to one's health.As is know, smoking is harmful to one's health.As是关系代词。
例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。关系代词that 的用法1）不用that的情况a） 在引导非限定性定语从句时。
（错） The tree, that is four hundred years old, is very famous here.b） 介词后不能用。We depend on the land from which we get our food.We depend on the land that/which we get our food from.2） 只能用that作为定语从句的关系代词的情况a） 在there be 句型中，只用that，不用which。
b） 在不定代词，如：anything, nothing, the one, all, much, few, any, little等作先行词时，只用that，不用which。c） 先行词有the only, the very修饰时，只用that。
d） 先行词为序数词、数词、形容词最高级时，只用that。.e） 先行词既有人，又有物时。
举例：All that is needed is a supply of oil.所需的只是供油问题。Finally, the thief handed everything that he had stolen to the police.那贼最终把偷的全部东西交给了警察。
难点分析（一）限制性定语从句只能用that的几种情况1.当先行词是anything, everything, nothing (something 除外)， few, all, none, little, some等代词时，或者是由every, any, all, some, no, little, few, much等修饰时（1） Have you taken down everything that Mr. Li has said?(2) There seems to be nothing that seems impossible for him in the world.(3) All that can be done has been done.(4) There is little that I can do for you.注意：当先行词指人时，偶尔也可以用who(4) Any man that/.who has a sense of duty won't do such a thing.2. 当先行词被序数词修饰（1） The first place that they visited in London was the Big Ben.3. 当先行词被形容词最高级修饰时（1） This is the best film that I have seen.4. 当形容词被the very, the only 修饰时（1） This is the very good dictionary that I want to buy,(2) After the fire in his house, the old car is the only thing that he owned.当先行词指人时，偶尔也可以用who(3) Wang Hua is the only person in our school who will attend the meeting/5. 当先行词前面有who, which等疑问代词时（1） Who is the man that is standing there?(2) Which is the T-shirt that fits me most?6. 当先行词既有人，也有动物或者物体时（1） Can you remember the scientist and his theory that we have learned？（二）关系代词as和which引导的定语从句as和which引导非限制性定语从句，有相同之处也有不同之处。具体情况是：1.As和which都可以在定语从句中做主语或者宾语，代表前面整个句子。
（1） He married her, as/which was natural.(2) He was honest, as/which we can see.2. as 引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一个主句；which引导的。