关系代词：
关系代词用来引导定语从句。它代表先行词，同时在从句中作一定的句子成分。关系代词有主格，宾格和属格之分，并有指人与指物之分。
关系代词有主格，宾格和属格（所有格）之分，并有指人与指物之分。that的用法最广，that 可指人也可指物。具体有哪些见表：
关系副词：
关系副词，兼有副词与连接词两种作用，在不及物动词的连接中要求用关系副词。所引导的形容词子句用于修饰主要子句中的某一名词或代名词，被修饰的词称作先行词，关系副词要放在先行词之后。例如：关系副词when在定语从句中用作状语，表示时间，用以修饰表示时间的先行词。
关系副词主要有三个，即when,where,why。
关系代词和关系副词的区别:
1、关系代词(that, who, whom, whose, which)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。
例1:Is he the man who/that wants to see you?(who / that在从句中作主语，指人);
例2:He is the man whom/ that I saw yesterday.(whom / that在从句中作宾语，指人);
例3:They rushed over to help the man whose car had broken
down.(whose在句中作定语，指人);
例4: Please pass me the book whose cover is green.(whose在句中作定语，指物。);
2、关系副词(when, where, why,)可代替的先行词是时间、地点或原因的名词，在从句中作状语。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1:Beijing is the place where (in which) I was born.
例2: Is this the reason why (for which) he refused our offer?
例3: His father died the year (when / in which) he was born.
例4:He can’t find the place (where / in which) he lived forty years ago.
关系副词:when where why
关系代词和关系副词的区别和用法
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
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 / 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。
What只能引导名词性从 句， 用作连接代词，作从句的具体成分，且不能省略。
I think (that) you will like the stamps.
What we need is more practice.
关系代词,关系副词,连词的区别
连接两个句子的词叫连接词,也叫引导词.
分成并列连词和主从连接词两种.
并列连接词是连接并列句的,有and but or for so nor.
主从连接词根据从句功能不同又可分为三种：1.纯连接词2.特殊疑问连接词 3.关系连接词4.连接副词
引导名词性从句的叫特殊疑问连接词(疑问代词what which whose who whom 疑问副词when where why how)和纯连接词（that whether if）,用来引导主语从句宾语从句补语从句同位语从句
引导定语从句的叫关系连接词,分为关系代词who whom which that whose和关系副词when where why 关系代词代替先行词在从句里充当一定主语宾语补语定语.关系副词代替先行词在从句里充当状语.
引导状语从句的叫连接副词,有when where why how,在状语从句里充当状语.
疑问代词有疑问意义,引导名词从句,无先行词（同位语从句有先行词）
关系代词无疑问意义,有先行词.引导定语从句
关系副词无疑问意义,有先行词.引导定语从句
连接副词无疑问意义,无先行词,引导状语从句
总体来说关系副词在定语从句中做状语
他们和关系代词主要的区别是where,when,why=介词+which
eg:This is the house in which (where) I lived last year.
This is the reason for which (why) he was late for school.
That's the day on which (when) I met him in the street.
关系副词:when where why 关系副词:先行词在从句中充当时间副词,地点副词,原因副词 判断定语从句中的谓语动词是及物动词还是不及物动词:若是及物动词且其后没有宾语,则选关系代词;若是有宾语,则选关系副词。若是不及物动词且其后没有介词,则选关系副词;若是有介词,缺少介词的宾语,则选关系代词。本回答被网友采纳
总体来说关系副词在定语从句中做状语
他们和关系代词主要的区别是where,when,why=介词+which
eg:This is the house in which (where) I lived last year.
This is the reason for which (why) he was late for school.
That's the day on which (when) I met him in the street.