in which. on which.for which.at which.of whom分别等于什么。例forwhich=why其用法是?

具体情况分析，表示时间的用when
地点用
where
例如和
live连用的时候
the
street
where
I
live=
the
street
in
which
I
live,
of
whom
=Whose
主要是看句子的意思。
再看看别人怎么说的。

没有分别等于什么，具体句子具体对待
比如The
room
in
which
I
was
born
remains
the
same.
这里=where
The
day
on
which
I
was
born
is
unknown.
这里
on
which=
when
The
year
in
which
i
was
born
is
unknown.
这里in
which=when
介词选择根据前面名词，或者后面动词来确定，
而关系副词when,where根据前面是时间，还是地点来确定。
你问这个问题，说明你定语从句基本不懂，建议你找点详细资料，好好学学。

供参考
不妨也试试用以下的角色来理解
which
方面
这主要与句中的
(1)
不及物动词所用的介词
或
(2)
或其它的介词
有关
例子
(1)
的例子
John
liked
the
book.
Mary
was
sitting
on
the
book.
留意
sitting
这个不及物动词用了
on
这个介词
如果将这2句用which
来连在一起
on
the
book
便成为了
on
which
John
liked
the
book,
on
which
Mary
was
sitting.
(2)
的例子
John
has
a
book.
In
the
book
there
are
a
lot
of
pictures.
留意
in
the
book
连成2句的话
可得出
John
has
a
book
in
which
there
are
a
lot
of
pictures.
值得留意的是
由於这里的
which
都是跟在介词之後的
所以在原句中是’宾语‘
sitting
on
the
book
中的
book
是宾语
in
the
book
中的
book
也是宾语
至於whom
概念都是一样
用上
of
因为原句中出现了
of
这个介词
而
whom
也是宾语
不同之处
乃是
whom
指人
which
指非人的生物或物件
例子
There
are
ten
students.
Many
of
them
are
hardworking.
留意
many
of
them
many
是主语
of
them
中的
them
是介词
of
的宾语
连成一句
得出
There
are
ten
students,
many
of
whom
are
hardworking.
再看以下的2句
John
stared
at
the
girl.
He
was
fond
of
the
girl.
留意
fond
of
the
girl.
连成一句
得出
John
stared
at
the
girl,
of
whom
he
was
fond.
for
which
=
why
?吗
其实for
有
because
之意
单以
for
which
来解理
其中一个可能的解释是‘为了这/它...'
这也许可以理解为
why
吧
如果能提供具体的句子
也许能够给点意见