情态动?/p>
(一)情态动词的含义?/p>
情态动词表示说话人对某一动作或状态的的态度?/p>
认为
“可能?/p>
?/p>
“应当?/p>
?/p>
“必要”等?/p>
情态动词不能单独作谓语,必须和不带
to
的动词不定式连用。情态动词没
有人称和数的变化?/p>
(二)几种主要的情态动词:
1.
表示可能的情态动?/p>
: may, might, could , can, must,
?/p>
1
?/p>
may
,
might,
could
都可以用来表示可能性,意思是“可能”,“也
许”,它既表示现在的可能性,也表示将来的可能性:
They may be waiting at the station.
You’d better take an umbrella. It might rain tonight.
The phone is ringing. It could be Tim.
I
haven’t
decided
where
to
spend
my holidays. I
may
go
to
Ireland.
The bus doesn’t always come on time. We might ha
ve to wait a few
minutes.
它们的否定形式是
:
may not, might not
意思是
“可能不?nbsp;
I’m
not
sure
whether
I
can
lend
you
any
money. I
may
not
have
enough
money.
It might not be true.
Ann may not come to the party tonight. She isn’t well.
?/p>
2
?/p>
may,
might,
could
后面?/p>
have
done
的形式,表示一种过去的可能
性,是对过去动作的推测?/p>
He may have left yesterday.
—?/p>
I wonder why he was in such a bad mood yesterday.
—?/p>
He may not have been feeling well.
He might have known about it.
Tom could have taken it; he was here along yesterday.
?/p>
3
?/p>
must
也表示比较有把握的推?/p>
,
是有一定事实基础之上的判?/p>
:
The police are stopping all cars. They must be looking for the
escaped prisoner.
The light is on. They must be at home.
You have been traveling all day. You must be very tired.
?/p>
4
?/p>
can
一般用在否定和疑问句中表示可能?/p>
.
You ha
ve just had lunch. You can’t be hungry already.