can may must should have to need 的区别

must
========================
v.aux.
1.
(表示必要、命令或强制)必须,得
You
mustn't
talk
like
that.
你可不能这样说话。
You
must
do
as
you
are
told.
你必须遵嘱行事。
We
must
be
home
by
six.
我们必须在六点以前回家。
2.
(表示肯定的推测)一定是,谅必,八成
This
must
be
your
room.
这一定是你的房间了。
He
must
be
eighty
now.
他现在八成有八十岁了。
3.
(表示不可避免性)必然要,必定会
All
men
must
die.
人总有一死。
4.
(表示主张)一定要,坚持要
If
you
must
go,
at
least
wait
till
the
rain
stops.
如果你坚持要走,至少也要等雨停了再走。
5.
(表示与说话人愿望相反)偏要
The
machine
must
break
down
at
this
busy
hour.
正忙的时候机器偏偏坏了。
n.[S]
1.
必须做的事;不可少的事物
A
walking
stick
is
a
must
for
me
now.
如今我行走离不开手杖了。
2.
一定要看(或听、读)的东西
a.
1.
绝对必要的,必须的[B]
===============================
have
to
表示客观的需要
eg.
Tom,come
out
to
play
with
us.
Sorry,
my
mom
said
i
have
to
finish
my
homework
first.
eg.
Do
you
have
to
leave
now?
yes,
i
must
eg
Do
i
have
to
eat
it
up,mom?
no,
you
needn't