高考英语之情态动词
高考英语之情态动词本文简介:情态动词助动词(auxiliary)主要有两类:基本助动词(primaryauxiliary)和情态助动词(modalauxiliary)。情态助动词有十三个:may,might;can,could;will,would;shall,should;must,need,dare,usedto,ough
高考英语之情态动词本文内容:
情态动词
助动词(auxiliary)主要有两类:基本助动词(primary
auxiliary)和情态助动词(modal
auxiliary)。情态助动词有十三个:may,might;
can,could;
will,would;
shall,should;
must,need,dare,used
to,ought
to.
上述两类助动词的共同特征是,在协助主动词构成限定动词词组时,具有作用词的功能:
情态助动词的特征
情态助动词有自己的词义,但是必须和实义动词连用,能表示说话人对有关动作或状态的看法,或表示主观设想。我个人认为可以把情态二字理解为感情(讨厌或是喜欢)和态度(赞成或是反对,还有推测)
1)
情态助动词在限定动词词组总是位居第一:
They
need
not
have
been
punished
so
severely.
2)
情态助动词用于第三人称单数现在时的时候,没有词形变化,即其词尾无-s形式:
She
dare
not
say
what
she
thinks.
3)
情态动词没有非限定形式,即没有不定式、-ing分词和-ed分词形式:
Still,she
needn’t
have
run
away.
4)
情态助动词的“时”的形式并不是时间区别的主要标志而是语气强弱的区别。在不少场合,情态助动词的现在时和过去时形式都可以表示现在、过去或将来时间:
Would
you
mind
if
I
ask
you
to
do
something?
She
told
him
he
ought
not
to
have
done
it.
Can
you
help
me?
Could
you
help
me?
后者就比前者的语气委婉的多。
情态助动词的意义和用法
情态助动词从最普通的意义上来说,是修饰分句意义的一种方式,它可以反映说话者对其表述是否真实和可能的程度作出判断。但不同的情态助动词本身所包含的意义和用法又不同,下面我们就例举几个常见的情态动词
1)
can和could的用法
1.
表示能力或客观可能性,还可以表示请求和允许。如:
I
can
speak
English.
Man
cannot
live
without
air.
—
Can
I
go
now?
—
Yes,you
can.
注意:①could也可表示请求,预期委婉,主要用于疑问句,不可用于肯定句,答语应用can(即could不能用于现在时态的简略答语中)。如:
Could
I
come
to
see
you
tomorrow?
Yes,you
can.
(否定答语可用No,I’m
afraid
not.)
②can表示能力时,还可用be
able
to代替。
同时我们过去的某种能力我们不采用can的过去式,而是用这个短语对应的过去,如:
I’ll
not
be
able
to
come
this
afternoon.
I
was
able
to
swim
across
the
river
when
I
was
5
years
old.
2.
表示惊异、怀疑、不相信的态度。(主要用在否定句、疑问句或惊叹句中)
Can
this
be
true?
How
can
you
be
so
careless!
This
cannot
be
done
by
him.
3.
“can(could)
+
have
+
过去分词”的疑问或否定形式表示对过去发生的行为怀疑或不肯定。如:
He
cannot
have
been
to
that
town.
Can
he
have
got
the
book?
2)
may和might的用法
1.
表示许可。
表示请求、允许时,might比many的语气更委婉一些,否定回答时要用mustn’t表示“不可以”、“禁止”、“阻止”之意。如:
You
may
drive
the
car.
—
Might
I
use
your
pen?
—
No,you
mustn’t.
用May
I
.
征询对方许可在文体上比较正式,在口气上比较客气。在日常口语中,用Can
I
.
征询对方意见在现代口语中更为常见。
2.
用于祈使句中表示祝愿。如:
May
you
succeed!
3.
表示推测、可能(疑问句不能用于此意)。
He
may
be
very
busy
now.
4.
“may(might)
+
have
+
过去分词”表示对过去发生的行为的推测。如:
He
may
not
have
finished
the
work.
3)
must和have
to的用法
1.
表示必须、必要。如:
You
must
come
in
time.
回答must引出的问句时,如果是否定的回答,不能用mustn’t,而要用needn’t或don’t
have
to。
—
Must
we
hand
in
our
exercise
books
today?
—
Yes,you
must.
(No,you
don’t
have
to.)
2.
“must
be
+
表语”的结构表示推测,它的否定或疑问式用can代替must。
This
must
be
your
pen.
3.
“must
+
have
+
过去分词”的结构常用在肯定句中,表示对过去发生的行为的推测。它的否定或疑问式用can代替must。
He
must
have
been
to
Shanghai.
4.
have
to的含义与must相似,两者往往可以互换使用,但have
to有各种形式,随have的变化而定。must与have
to有下列几点不同:
①
must表示的是说话人的主观看法,而have
to则往往强调客观需要。如:
The
play
is
not
interesting.
I
really
must
go
now.
I
had
to
work
when
I
was
your
age.
5.must
表示固执,偏偏
Why
must
you
be
talking
so
loudly
while
others
are
studying?
为什么在别人学习的时候,你非得这么大声地说话?
4)
shall和should的用法
1.
Shall用于第一人称,表示征求对方的意愿。如:
What
shall
we
do
this
evening?
2.
Shall用于第一、第三人称疑问句中,表示说话人征求对方的意见或向对方请示。如:
Shall
we
begin
our
lesson?
When
shall
he
be
able
to
leave
the
hospital?
3.
Shall用于第二、第三人称,表示说话人给对方命令、警告、允诺或威胁。如:
You
shall
fail
if
you
don’t
work
harder.
(警告)
You
shall
get
the
bike
if
you
get
full
marks
in
the
exam.(允诺)
4.
Should表示劝告、建议、命令,其同义词是ought
to;在疑问句中,通常用should代替ought
to。如:
You
should
go
to
class
right
away.
Should
I
open
the
window?
5)
will和would的用法
1.
表示请求、建议等,would比will委婉客气。如:
Would
you
pass
me
the
book?
2.
表示意志、愿望和决心。如:
I
will
never
do
that
again.
They
asked
if
we
would
do
that
again.
3.will可以表示一种习惯性的动作,总是或总要之意
Every
morning
he
will
have
a
walk
along
the
river.
4.Would可表示过去反复发生的动作或某中倾向。Would表过去习惯时比used
to正式,并没有“现已无此习惯”的含义。如:
The
wound
would
not
heal.
During
the
vacation
he
would
visit
me
every
week.
6)
ought
to的用法
1.
Ought
to表示应该。如:
You
ought
to
take
care
of
him.
2.
表示推测。注意与must表示推测时的区别:
He
must
be
at
home
by
now.
(断定他已到家)
He
ought
to
be
home
by
now.
(不十分肯定)
This
is
where
the
oil
must
be.
(比较直率)
This
is
where
the
oil
ought
to
be.
(比较含蓄)
3.
“ought
to
+
have
+
过去分词”表示过去应做某事而实际未做。如:
You
ought
to
have
asked
him
(but
you
didn’t).
这时,ought
to和should可以互相换用。
注意:在美国英语中,ought
to用于否定句和疑问句时,to可以省略。如:
Ought
you
smoke
so
much?
You
oughtn’t
smoke
so
much.
情态动词+have
done”的用法
1
Must
+
have
done
表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句。
1.
It
must
have
rained
last
night,for
the
ground
is
wet.
昨晚一定下雨了,因为地面还是湿的。
2.
You
must
have
been
mad
to
speak
to
the
servant.
你和仆人说话,一定是发疯了。
2
should
+
have
done
表示“本来应该做某事而实际上未做”,而shouldn’t
have
done则表示“本不应该做某事而实际上做了”。如:
You
should
have
told
me
about
it
earlier.
You
shouldn’t
have
said
such
words
to
your
parents.
3
ought
to
have
done也表示“本应该……”而ought
not
to
have
done则意为“本不应该……”。如:
You
ought
to
have
told
me
about
it
earlier.
You
ought
not
to
have
said
such
words
to
your
parents.
4
needn’t
have
done表示“本无必要做某事而实际上做了”。如:
You
needn’t
have
walked
so
quickly
since
time
was
enough.
5
could
have
done表示“本来有可能……而事实上未做到”。如:
I
could
have
come
on
time,but
my
car
broke
on
the
way.
6
may/might
+have
done
表示对过去行为的推测,可能做过。Might
表示的可能性更小语气更委婉。Might
have
done可表示本可能做而实际没有做。
I
can
not
find
my
purse
anywhere.
You
may
have
lost
it
while
shopping.
![](http://yyk.iask.sina.com.cn/pic/fimg/160992407799876974546.jpg)