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高考英语语法:助动词与情态动词
(一)助动词有
be,
have,
do,
will,
shall
p>
。它们本身没有词义,只和实义动词的一定形式构成复合谓语,
用来
表示时态和语态,构成否定、疑问及加强语气等。
1
、
be (am, is,
are, were, been)
(l)
“
be + -ing
”构成进
行时态;
(
2
)
“
be +
过去分词”构成被动语态;
(
3
)
“
be +
动词不定式”构成复合
谓语:①表示按计划安排要发
生的事。
The prime minister is to visit
Japan next year.
总理将于明年访问
日本。②
用于命令。
You're to do your
homework before you watch
TV.
你得做完了作业才能看电视。
2
、
have (has,
had)
(1)
“
have+
过去分词”构成完成时态。如:
Ha
ve you seen the film ?
(2)
“
have been + -ing
< br>”构成完成
进行时态。如:
What have you
been doing these days?
这些日子你一直在干什么
?
3
、
do (does, did)
(1)
“
do not +
动词原形”构成行为动词的否定式。如:His brother doesn’t
like playing
basket.;
(2)
“
Do +
主语
+
动词原形”构成行为动词的一般疑问句。
Does he go
to school by bike every day?
(3)
“
do +
动词原形”用于祈使句或陈述句中表示加强语气。如:I did go to see
him, but he wasn’t in
我确
实去看望他
了,
但他不在家。
Do
do
some
work.
请一定做点什
么;
(4)
代替前面刚出现的动词以避免重复。
My
mother
told me to go
to bed early. So I did.
, shall
(would, should)
“
will (shall
+
动词原形”构成一般将来时,一般来说
shall
用于第一人称,
will
用于第二人称或第三人<
/p>
(二)情态动词
情态动词表示说话人对某一动作或状态的态度,可以表示“可能”
、
“可以”
、
“需要”
、<
/p>
“必须”或“应当”等
之意。情态动词没有人称和数的变化。但不
能单独作谓语动词用,必须和不带
to
的不定式连用构成谓语动
词。
只有情态动词
ought
要和带<
/p>
to
的动词不定式连用,在句中作谓语用。
将情态动词置于主语之前即构成其疑问式,在情态动
词之后加
not
既构成其否定式。现将各情态动词的基本
用法分述如下:
1
、
can
和
could (could
为
can
的过去式
)
的基本用法
(1)
表示能力,如:
He
can speak English better than you. (2)
在
疑问句和否定句中表示“怀疑”
、
“猜测”
或“可能性”
,如:
Can
this
green
bike
be
Liu
Dong's?
p>
(3)
表示“许可”时
can
可以和
may
换用,如:
Y
ou
can
(may)
go
home
now.
(4)
如果要表示语气婉转,
可用
could
代替
can
,
这时
p>
could
不再是
can
< br>的过去式,
如:
Could
you come again tomorrow?
(5)can
和
be able to
都可表示能力,两者在意思上没有什么区别。但是
can
只能<
/p>
有现在式和过去式,而
be able
to
则有更多的形式,如:
He will be able
to do the work better.
2<
/p>
、
may
和
mi
ght (might
为
may
的过去
式
)
的基本用法
(1)
表示允许或征询对方许可,有“可以”之意,如:
You
may use my dictionary.
在回答对方说“可以做
某事”或“不可以做某事”时,一般多不用
may
或
may
not
,以避免语气生硬或
不容气。而用比较婉转的说法进
行回答。如:
---- May
I use this dictionary? ---- Yes, please.
或
---- Certainly.
在请求对方许可时,
如果
Might
I
…
?
就比用
May
I
…
?
语气更婉转些,如:
May I have a look
at your new computer?
但是表示
“阻
止”或“禁止”对方做某事时,要用
must
not
代替
may
not
,如:
---- May we swim in
this lake? ----
No, you mustn’t. It’s
t
oo dangerous.
(2)may
或
might
都可以表
示可能性,表示“或许”
、
“可能”之意,
如果用
might
表示可能性,则语气更加不肯定,如:<
/p>
They may (might) be in the library now
.
称,口语中常用
will
代替
p>
shll
,如:
We will have
a meeting to discuss the problem.
3
、
must
的基本用法
用心
爱心
专心
1
(1)must
表示“必须”
p>
、
“应该”之意,其否定式
must
not
,缩写形式为
mustn't
,表示“不应该”
,
“不准”
、
“不许可”或“禁止”之意,如:
We
must study hard and make progress every day. You
mustn't touch the
fire. (2)
对
以
must
提出的疑问句,如作否定回答时,要用
needn't
或用
don't
(doesn't) have to (
不
必
)
来
回答,而不用
mustn't
,因为
mustn't
表示的是“禁止”或“不许可”之意,如:
----
Must
we
finish
the
work
tomorrow? ---- No, you needn't (don't
have to), but you must finish it in three days.
(3)
在肯定
句中
must
可以表示推测,表示“一定”或“必定”之意,如:
---- Whose
new bike can it be? ---- It must
be Liu
Dong's. I know his father has just bought him a
new one.
4
、
can,
could, may, must
后接完成式的用法
(1)can,
could
后接完成
式的用法:①在否定句或疑问句中表示对过去发生过的事情的“怀疑”或“不肯定”
的态
度,
Could he have said so?
②在肯
定句中,可以表示过去可能做到而实际并没做到的事情,有“劝告”
或“责备”的语气。
如:
---- When did you answer her letter?
---- Only yesterday. ---- It's too late.
You could have answered it earlier, I
am sure. (2)may,
might
后接完成式的用法
①表示
对过去某事的推
测,认为某一件事情在过去可能发生了。如果使用
might
,语气就比较婉转或更加不肯定,如:
Mary
might
have
learned some Chinese before.
②可以表示过去本来可以做到而实
际
没有做到的事情,有“劝告”或“责备”
的语气,如:
You
didn't do the work well that day. You might have
done it better. (3)must
后接完成
式
的用法:表示对过去某事的推测,认为某事在过去一定做到
了,如:Liu
Dong
isn’t
in
the
classroom.
He
must have gone to the library.
5
、
have
to
的基本用法:
have
to
和
must
的意
义相近,只是
must
侧重表示说话人的主观看法,而
have
to
6
、
ought
to
的基本用法
(l)
表示根据某种义务或必要
“应当”
做某事,
语气比
should
强,
例如:
Everyone
ought
to
obey
the
traffic
regulations.
(2)
表示推测,
注意与
mu
st
表示推测时的区别:
He
must
be
home
by
now
.(
< br>断定他已到家
)
,
He
ought
to
be
home
by
now
.(
不十分肯定
)
,
p>
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
+
have+
过去分词”表示过去应做某事而
实际未做。例如:
You
ought
to
have
helped
him. (but you didn’t)
这时,
ought
与
should
可以互相换用。注意,在美国英语中
ought
to
用于
否定和疑问句时
to
可以省略。例如:
Ought you smoke so
much?
You oughtn’t smoke so
much.
则表示客观需要,如:
I must study hard.
I had to give it up because of illness.
7
、
dare
的基本用法
(l)dare
(dared
为其过去式
)
作情态动词用时,
主要用于否定句,
疑问句和条
件从句中,
如:
Dared
he
bread
the traffic
regulations again? (2)
在现代英语中
dare
常用作行为动词,其变化与一般行为动词相同,如:
S
he dares to stay at home alone at night.
8
、
need
的基本用法
(1)need
作情态动词用时,主要用于否
定句和疑问句中,如:
He needn't worry about us
now. (2)need
也可作为行为动词用,可用于肯定句,否定句和疑问句中,
其后可接名词、代词、动名词或带
to
的动词不定式
为其宾语。如:
You
need to practise reading aloud every day. (3)needn
't
后接完成式可以表示过去做了
一件本来不必要做的事情,如
:
---- Did you answer the letter
yesterday? ---- Yes, I did. ---- But you
needn’t have answered it.
p>
9
、
shall
的
基本用法
(1)shall
用作情态
动词时,用于第二、三人称,表示说活人的意愿,可表示“命令”
、
“警告”
、
“强制”
、
“威
胁”或“允诺”等意,如:
He shall
go first, whether he wants to or not. (2)
在疑问句中,
shall
用于第
一
、三人称,表示说话人的征询对方意见或请求指示,如:
Shall I open
the door?
10
、
shou
ld
的基本用法
用心
爱心
专心
2
(
1)should
作为情态动词可以表示“建议”或“劝告”
,
有“应该”之意,如:
You
should
learn
from
each
other. (2)should
后接完成式表示过去没有做
到本来应该做的事情,或是做了本来不应该做的事情。如:
You
should have give him more help.
11
、
will
的基本用法
(1)
用于各人称,可以表示“意志
”或“决心”
,如:
I have told him
again and again to stop smoking,
but he
will not listen. (2)
在疑问句中用于第二人称,表示说话人向对
方提出请求或询问对方的意愿,如:
Will you please tell me
how to get to the Capital Gymnasium? (3)will
可以表示一种习惯性的动作,有
“总是”或“会要”之意,如:
Every morning he will have a walk along this
river.
12
、
would
p>
的基本用法
(1)would<
/p>
作为
will
的过去式,可用于各人称,
表示过去时间的“意志”或“决心”
,如:
He
promised he
would never
smoke again. (2)
在疑问句中,用于第二人称,表示说话人向对方提出
请求或许问对方的意愿时,
比用
will
的气更加婉转,如:
Would
you
like
some
more
coffee?
(3)
在日常生活中,学用“
I
would
like
to
…”
表示“我想要”或“我愿意”之意,以使语气婉转,如:
I would like to do Ex.2 first. (4)would< p>
可以表示
过去的习惯动作,比
used
to
正式,并没有“现已无此习惯”的含义。如:
Last
year
our
English
teacher
would
sometimes tell
us stories in English after class. /
During the vacation
he would visit me
every
week.
(5)
表料想或猜想,如:
It
would
be
about
ten
when
he
left
home./
What
would
she
be
doing
there?/
I
thought
he would have told
you about it.
13
、
used to, had
better, would rather
的用法
(1)used
to
表示过去的习惯
动作或状态,现在已不存在,在间接引语中,其形式可不变,例如:
He
told
us
he used
to play foot ball when he was young.
在疑
问句、否定句、否定疑问句或强调句中,可有两种形式。
疑问句:
Did you use to/ Used you to go to the same school
as your brother?
否定句:
I
usedn’t to /
didn’t use to
go there. (usedn’t
也可写作
usen’t);否定疑问句:Usen’t you to/ Didn’t
you use to
be interested in the
theatre?
强调句:
I certainly
used to/ did use to smoke, but it was a long time
ago.
;其反意疑问句或简略回答中,也有两种形式:She
used
to
be
very
fat.
didn’t
she?/
use(d)n’t
she?
Did you use to play
chess? Yes, I did./ Used you to get up early in
the morning? Yes, I did./ used
to.
(2)had better
意为“最好”
,后接不带
to
的不定式,例如:
---- We had
better go now . ---- Yes, we
had (we'd
better/ we had better).
/ Hadn’t we
better stop now? (Had we better not stop now?)/ I
think
I’d better be going.
(
用于进行时态,表“最好立即”
)/
You had better have done that
(
用于完成时态,
表未完成动作
)
注:
had better
用于同辈或
小辈,对长辈不可用。
(3)would rather
意为“
宁愿”
,表选择,后
接不带
to
的不定式,例如:I’d
rather
not
say
anything./
Would
you
rather
work
on
a
farm?/
----
Wouldn’t
you
rather stay here? ----
No, I would not.
I’d rather go there. 由于
would
rather
表选择,因
而后
可接
than
,例如:
I would rather work on a farm than in a factory.
/ I would rather watch TV than go
to
see the film/ I would rather lose a dozen cherry
trees than that you should tell me one lie./ I’d
rather you didn’t talk about this to
anyone.
(
句中的
'd
rather
不是情态动词,
would
在此是表愿望的
实义动词
)
用心
爱心
专心
3
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