第1个回答 2020-01-14
MUST
做情态动词的否定形式
就是needn't或can't
,couldn't等
但绝对不是mustn't
这个可以说是约定俗成的,只有这个用法,记住就是了
1)
表示必须、必要。
You
must
come
in
time.
在回答引出的问句时,如果是否定的,不能用mustn’t(禁止,不准),而用needn’t,
don’t
have
to(不必).
----
Must
we
hand
in
our
exercise
books
today?
----
Yes,
you
must.
----
No,
you
don’t
have
to
/
you
needn’t.
2)
must是说话人的主观看法,
而have
to则强调客观需要。Must只有一般现在时,
have
to
有更多的时态形式。
1.
he
play
isn’t
interesting,
I
really
must
go
now.
2.
I
had
to
work
when
I
was
your
age.
3)
表示推测、可能性(只用于肯定的陈述句)
1.
You’re
Tom’s
good
friend,
so
you
must
know
what
he
likes
best.
2.
Your
mother
must
be
waiting
for
you
now.