He has a knife with which to defend himself.

Question

如题所述

Answer 1

“介词+which”后接不定式短语作后置定语，相当于一个定语从句。
He
has
a
knife
with
which
to
defend
himself.
他有一把自卫的刀。
同类例句：
Allow
me
half
an
hour
in
which
to
wash
the
clothes.
留给我半小时洗衣服。
He
had
no
pretext
on
which
to
break
his
promise.
他没有违背诺言的借口。
She
has
saved
another
thousand
dollars
with
which
to
support
her
family.
她又存了1000美元用以接济家庭。

Answer 2

这是一个定语从句
先行词是knife
所以引导词用Which或that
但介词后不能用that
固定用法
defend
with用……防卫
这里把with提到引导词前

Answer 3

“介词+关系代词”后接不定式短语作后置定语，相当于一个定语从句。
He
has
a
knife
with
which
to
defend
himself.
=
He
has
a
knife
with
which
he
can
defend
himself