in which，for which，on which，at which有什么区别，怎么使用，用法

in
which,
for
which,
on
which,
at
which的不同用法
　　1)这些都是定语从句里面，由which引导的定语从句，介词提前。下面这些介词的使用除了意思上的区别，具体是要以which引导的从句而定的。
　　①in
which可以翻译成在……里面
　　The
school
(that/which)
he
once
studied
in
is
very
famous.
　　=
The
school
in
which
he
once
studied
is
very
famous.
　　②for
which可以翻译成为了……目的
　　Tomorrow
I
will
bring
here
a
magazine
(that/which)
you
asked
for.
　　=
Tomorrow
I
will
bring
here
a
magazine
for
which
you
asked.
　　③on
which可以翻译成在……的上面，或具体时间的某一天
　　I
have
a
dresser
in
my
bedroom,
which
there
are
many
cosmetics
on.
　　=
I
have
a
dresser
in
my
bedroom
on
which
there
are
many
cosmetics.
　　④at
which可以翻译成在……里面或在……
　　The
dumpling
House
which
he
often
has
dumplings
at
is
very
popular.
　　=
The
dumpling
House
is
very
popular,
at
which
he
often
has
dumplings.
　　2)当然第一点只是介词作为基本意思的用法，还有一些固定搭配，得具体情况具体分析。
　　①The
plane
may
be
several
hours
late,
in
which
case
there’s
no
point
in
our
waiting.
　　(固定搭配：in
the
case)
　　②The
speaker
paused
to
examine
his
notes,
at
which
point
a
loud
crash
was
heard.
　　(固定搭配：at
the
point)
　　③Ten
years
of
hard
work
changed
her
greatly,
for
which
reason
he
could
hardly
recognize
her
at
first
sight.
　　(固定搭配：for
the
reason)
　　④The
film
at
which
I
fell
asleep
was
very
boring.
　　(Here
"at
which"
is
based
on
"fell
asleep
at
the
film"因为电影无聊而睡觉。)
　　⑤The
little
creature
in
which
scientists
are
interested
is
known
as
ET.
　　(这里"be
interested
in"是词组原因)
　　⑥This
is
the
book
for
which
he
is
looking.
　　(即等于This
is
the
book
which
he
is
looking
for，这主要是因为look
for
这一短语)

主要看从句中的不及物动词,比如for
which.
我们可以造个句子方便理解:this
is
the
book
for
which
he
is
looking.即等于this
is
the
book
which
he
is
looking
for.这主要是因为look
for
这一短语.
which在从句中做宾语,如上句,还原就是
he
is
looking
for
which.
其中in
which≈where,
这里就不赘述了.
希望这样能对您有所帮助~呵呵