关系代词
关系代词是一种引导从句并起连接主句和从句作用的代词关系词。关系代词有 who, whose, whom, that, which. 它们在句中可用作主语,表语,宾语,定语. 在主句中,它们还代表着从句所修饰的那个名词或代词。例如：
I hate people who talk much but do little.
I’m looking at the photograph which you sent me with your letter.
With the money that he had saved, he went on with his studies.
Do you know the lady who is interviewing our headmaster?
关系副词，
在句子中做状语，高中常见的就是，where ,when如：
地点状语： My father works in the factory where we visited in last month.
时间状语： I still remember the time when my mother told me the news.
其他的还有方式状语，让步状语，原因状语。他们在句子中相当于一个副词用。
关系代词 指代作用 和关系副词不指代，句子不缺成分，只做状语用。
相信你已经明白，希望对你有用。
引导定语从句的关系词分：关系代词和关系副词，用法如下：
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.
