1,that作
指示代词,比如
This
is
my
father.
2,就是你说的关系代词,引导限定性定语从句。在下列情况下多用that:
先行词既有人又有物时;先行词有形容词最高级、序数词、
不定代词、very,only等修饰时;先行词是不定代词时)
He
talked
about
the
teachers
and
schools
that
he
had
visited.
I
think
it
one
of
the
most
wonderful
films
that
the
film
company
has
ever
produced.
She
has
little
information
that
is
useful
for
our
research.
Is
there
anything
that
I
can
do
for
you?
3,引导
宾语从句,主语从句等。