1. whose 为 who 的所有格，作 “某人的……” 的意思，它所指代的先行词必须是人，其引导的定语从句修饰它的先行词，同时它本身在从句中作定语。
This is the little girl whose parents were killed in the great earthquake.
The teacher wants to talk to the student whose homework hasn’t beenhanded in.
2. whose 可作 which 的所有格，作 “某物的…”的意思，它所指代的先行词必须是物，其引导的定语从句修饰它的先行词，同时它本身在从句中作定语
The company whose name is Tesla is in the United States.
We live in a house whose windows open to the south.
3. whose 可修饰定语从句中的主语、宾语、介词宾语等不同成分。
His grandpa, whose arms were badly hurt, was quickly taken tohospital.(whose 修饰定语从句中的主语 arms)
We have to make a decision about my cousin, whose story I’ve just told you.(whose 修饰定语从句中的宾语 story)
4.whose 既可引导限制性定语从句，亦可引导非限制性定语从句。
Mike whose ambition is to become an astronaut, always works hard. (非限制性定语从句)
Could you pass me the notebook whose cover is brown? (限制性定语从句)
5. 由于 whose 具有兼作 who 和 which 的所有格的双重功能，故在指人时可用 of whom 代替 whose，指物时可用 of which 代替 whose。
This kind of book is for children whose native language =the native language of whom) is Chinese.
Billy has written a novel whose name (=the name of which) l’ve completely forgotten.
下列情况中的 whose 和 of whom 或 of which 不可混用
1. 当 of whom 或 of which 同数词或代词 (如 some, many, little 等) 连用表示部分与整体关系时，通常不可用 whose
There are 45 students in our class, 35 of whom are League members
Dr.Sue wrote many books for kids, some of which were translated into Chinese.
2. 当 of whom 或 of which 修饰定语从句中的主语，是表示同位关系的代词 both, all 等时，都不能用 whose
l have two sons, both of whom are soldiers.
He has some novels, all of which are written in German.
关系代词 which 的用法
关系词 which 的造句结构类似于 who，可以作从句的主语或宾语，区别在于 which 的先行词是 “物”；而 who 的先行词是 “人”。但 which 所指代的先行词比较复杂一些，它除了可以指单个的名词，也可以指代短语甚至从句。
1. 先行词是单个名词
A computer is a machine which can do many things for us. (先行词是 computer, which 作定语从句主语)
2. 先行词是一个短语
He likes playing golf, which is a good exercise. (先行词是一个短语 playing golf , which 作定语从句主语)
3. 先行词是一个句子
Tina was late, which surprised me. (先行词是前面的整个句子，which 作定语从句主语)
关系代词 that 的用法
关系代词 that 既可以指 “人” 也可以指 “物”，因此 that —般可用来 替换 which 或 who。作宾语时常常可省略。
The foreigners that/who visited our school yesterday are from Canada.
l like the book (that/which) my uncle gave me.
既然 that 既可以指 “人” 也可以指 “物”，that 与 which 和 who 在用法上有哪些区别呢?
1. 当先行词中同时出现“人”和“物”时，用 that
The writer and his novels that the article deals with are quite familiar to us. (关系代词 that 在从句中作宾语)
2. 先行词为指 “物” 的 all, little, few, much 和 none 时，用 that
All that we need to do now is to practice English. (关系代词 that 在从句中作宾语)
There is not much that can be done. (关系代词 that 在从句中作主语)
This article contains little that is useful.(关系代词that在从句中作主语)
3. 先行词有最高级或形容词最高级修饰时，用 that
Tom is the cleverest boy that l have ever known.
This is the first play that l have seen since l came here.
4. 先行词是不定代词 something, anything, nothing 和 everything 时，一般用 that
l refuse to accept the blame for something that is someone else’ s fault.
l would much rather receive a gift that was unique or that l knew myfriend had put some thought into than something that cost a lot of money but that l didn’ t need or want.
5. 先行词被 any, only, all, every, no, some, much, few, little, the only, the one, the very 和 the right 等成分修饰时，用 that
I’ve read all the books that you lend me.
There is no difficulty that they can’t overcome.
The only thing that we should do is to clam down right now.
The very problem that l want to solve is like this.
6. that 不能用于介词后和非限制性定语从句中
关系副词 when 的用法
一、先行词指时间
when 可以引导限制性和非限制性定语从句，其先行词须是表示时间的名词，如 day, year 或 time 等。
引导限制性定语从句
Jack will never forget the day when he met Rose.
As the smallest child of his family, Alex is always longing for the time when he should be able to be independent.
引导非限制性定语从句
My favorite season is summer, when l can eat lots of watermelon and icecream.
He will put off the picnic until May 1st, when he won’ t be so busy.
二、关系副词 when 在从句中作时间状语
when 是在定语从句中作时间状语。提醒大家一定要注意，若定语从句中缺少的不是状语，而是主语或宾语，那么即使先行词是表示时间的名词，也不能用 when 而要用 which 或 that 来引导定语从句。用 when 来导定语从句的前提条件是： when 必须在其引导的定语从句中作时间状语。
I’ll never forget the time which l spent with my family.
I’ll never forget the day when l started my own busiiness.
在这两句话里，尽管先行词分别是表示时间的名词 time 和 day，但用的关系词是不同的。在上面的句子当中，由于定语从句中的谓语缺少宾语，因此关系词要充当其中的宾语，所以要用 which。
在下面的句子当中，定语从句中不缺主语或宾语，而是缺少时间状语，所以关系词用 when，这里的 when 作时间状语。
关系副词 where 的用法
一、先行词指地点
where 引导定语从句，其先行词一般是表示地点的名词，如 place, house 等等。
This is the place where l cook my lunch.
Literature is the place where the past meets the present to contemplate the future.
Remember that the best relationship is one where your love for each other is greater than your need for each other.
二、关系副词 where 在从句中作地点状语
并不是所有表示地点的先行词都得由 where 来引导从句。还是需要看关系词在从句中充当的成分。如果定语从句缺少主语或宾语，则需要用 which 或 that 引导定语从句。
lt’s one of the few countries where people drive on the left.
l can’t remember all the places that we visited in Thailand.
在这两句话里，尽管先行词都是表示地点的名词，但用的关系词是不同的。在上面的句子当中，定语从句中不缺主语或宾语，而是缺少地点状语，所以关系词用 where，这里的 where 作地点状语。在下面的句子当中，由于定语从句中的谓语缺少主语，因此关系词要充当其中的主语，所以要用 that
关系副词 why 的用法
关系副词 why 引导限定性定语从句修饰先行词 reason，在定语从句中充当原因状语。
l don’ t know the reason why he came so late.
That is the reason why l don’t want to go.
He didn’ t tell me the reason why he was so upset.
An elephant, which is the earth’ s largest land mammal, has few natural enemies other than human beings. 这里的 an elephant 是泛指，表示 “大象” 这一类动物，而不是具体的某一头，所以用非限制性定语从句。