-
情态动词
+ have done
重点
1. Something
may have happened to her.
她可能发生了什么事情。
She might have had an accident.
她或许遭受了意外
.
So she must have taken that
too.
因此,她肯定把它也带走了。
1)
这三句话都用了“情态动词+
不定式的完成时”
,表示对发生过的事作某种猜测、推测。
(1)
must
have
done
可用来对某件过
去的事情作肯定推测,表示“一定已经,想必已经”做
过某事,用于肯定的陈述句中。否
定句中用
can't have
done
。
She must have received the parcel, I
sent it by registered post.
她一定已经收到包裹了,我是用挂号寄的。
(2)
may have
done, might have done, could have done
“
可能做过某事”
,
就语气而言
could have
done
所表的可能性更小些。
He may / might / could have left by
nine.
他可能于九点前已离去。
(3)
should have done / ought
to have done
表示“本该做某事”但实际未做。
I should / ought to have left London
before nine but I didn't.
我本该在九点以前离开伦敦,但是我没有。
(4)
shouldn't
have done / oughtn't to have done
表示“本不
该做事”
,但实际上又做了。
He shouldn't / oughtn't to have left
London before nine but he did.
他本不该在九点前离开伦敦,但是他离开了。
(5)
can't /
couldn't have done
表否定推测,
“不可
能做过某事”
。
She can't / couldn't have gone to bed,
for the light in her room is still on.
她不可能上床睡觉了,因为她房间的灯还亮着。
(6)
could have
done
可表示客观上“本来能做某事但实际上没做”
。
p>
He could have
finished the work in time but he didn't work hard.
他本来可以按时干完活的,但他没有卖力。
(7)
needn't have
done
表示客观上“本不必做某事但实际上又做了”
。
p>
I needn't have
gone to the office yesterday (but I went there).
昨天我没必要去办公室(但我却去了)
。
(8)
might
have
done <
/p>
还可表示过去“本可能发生但实际上没有发生的动作”
。用于表示
说话
人对已发生的事提出批评或意见。
He might have given more
help, even though he was very busy.
即使他很忙,也可以多帮点忙。
情态动词
+
动词完成式即“
情态动词
+
动词完成式即“情态动词
+
have + done
”
,表示
对过
去行为或动作进行推测、评论或判断。这个结构是近几年高考情态动词的重点和难点。
一、在虚拟语气中的用法
1. should have done
表示
“过去本应该做某事却未做。
”
< br>其否定结构
shouldn't have done
表示
“过去本不该做某事却做了。
”
2. ought to have done
表示
“过去本应该做某事却未做。
”
其否定结构
oughtn't to have
done
表
示“过去本不该做某事却做了。
< br>”
3. need
have done
表示“过去本有必要做某事却未做。
”其
否定结构
needn't have done
表示
“过去本没必要做某事却做了。
”
4. could
(
不能用
can) have
done
表示
“过去本能够做某事却未做。
< br>”
注意:
其否定形式
couldn't
have done
没有虚拟语气的用法,
couldn't have done
只能表推测,相当于
can't
have done
,
意为:
“过去不
可能做了某事。
”
5.
might
(
不能用
may)
have
done
表示“过去本可以做某事却未做。
”
注意:其否定形式
might
not have done
没有虚拟语气的用法,
might not have
done
只能表推测,
相当于
may not
have done
,意为:
“过去可能没有做某事。
”
二、表推测的用法
1. must have done
表示对过去某事的肯定猜测,译为:过去肯定做了某事。不存在
mustn't have done
的形式。
其否定或疑问形式须用
can(could)
来表示
.
例如:
Since the
road is wet, it must have rained
last
night.
既然路是湿的,那昨天晚上肯定下雨了。
He can't have missed the
way. I drew him a map.
他不可能迷路。我(当时)给他画了张图。
“
The dictionary
has disappeared. Who could have taken it?
”词典不见了,
(过去)谁可能把它
拿走了?
2. may / might have
done
may / might have done
表示“过去可能做了某事”
。
may
比
might
表示的可能性在说话人看
来稍大些。
may/might
not have done
表示
“过去可能没有做某事。
p>
”
例如:
I
can't find my keys.
I may / might have
left them at the school yesterday.
我找不到
我的钥匙了。我可能昨天把他们
落在学校了。
John
may/might not have passed the exam; he looks very
sad.
约翰可能没有通过考
试。他看起来很忧伤。注意:
p>
may/might have
done
表推测不能用于疑问句中。
3. can/could have done
表推测一般用在否定句和疑问句中,表示不相信或怀疑的态度。
Can/Could he have passed
the exam?
他可能通过了考试吗?
I think that he
couldn
’
t/can't have gone
abroad. I saw him just now.
我认为他不可能出国了。我
刚才还看见他了。
注:
表示推测过去某动作发生的可能性时,
就表示的可
能性程度而言,
must
最大,
could
其
次,
may
更次之,
might
最小。例如:
“
I wonder
how Tom knew about your
past.
”
“我想知
道汤姆是怎么知道你的过去的。
”
“
He must / could / may / might have heard of it
from Mary.
”
“他肯定
/
很可能
/<
/p>
可能
/
兴许(没准儿)已从玛丽那儿听说
此事了。
”
“情态动词+
have
done
”考点解析
“情态动词+
have done
”结
构是重要考点,也是较难掌握的语法项目之一,
为了帮助同学们更好地掌握使用这一考点
,
下面结合近年高考试题谈谈其主要用
法。
考点之一:
在虚拟条件句中,
如
果表示与过去事实相反的情况,
从句中用过
去完成时,而主句中
则用“情态动词+现在完成时”,即:
would/ could/ should/
might have
done
。例如:
If they
had finished the work on time, they would have
been praised by the
manager.
If you had worked hard, you could have
passed the examination.
考题分析:
1. If it
___ for the snow, we ___ the mountain yesterday.
A.
were not; could have climbed
B. were not;
could
C. had not been; could have climbed
D.
had not been; could climb
2.
--- I stayed at a hotel while in New York. --- Oh,
did you?
You ___ with
Barbara.
A. could have stay
B. could stay
C. would stay
D. must have
stay
3. Yesterday Jane
walked away for discussion, otherwise, she ___
something she
would regret
later.
A. had said
B. said
C. might say
D. might have said
答案简析:
1.
根据信息词
yesterday
可以判
断该句是表示与过去事实相反的虚拟条件
句,从句中应该用“情态动词+现在完成时”,
故答案选
C
。
2.
本句是一个含蓄虚拟条件句,意思是:
If you
hadn’t stay at a hotel while in
New
York, you could have stayed with Barbara.
< br>表达了与过去事实相反的情况,
答
案选
< br>A
。
3.
< br>本句考查的也是含蓄虚拟语气,
意思是:
如果她参加了讨
论,
她可能会说
出一些后来令她后悔的话。表达了与过去事实相
反的情况,故答案选
D
。
考点之二:
must have done
表示对过去已经发生过的情况的肯定推测判断,
语气较强,意思是“一定??、肯定
??”。其否定形式分别用
can’t/
couldn’t
和
can/
could
。例如:
It must
have rained last night, for the ground is wet this
morning.
昨天晚上一定是下雨了,因为今晨地面是潮湿的。
She didn’t attend the lesson yesterday.
She must have
been ill.
她昨天没有上课,她一定是生病了。
1.
Must have done
语气极强,表示非常肯定,一定做了某事,基本只用肯定句
巩固练习
.
He ____ have completed his work,
otherwise, he wouldn’t be enjoying himself
by the seaside.
A. should
B. must
C. wouldn’t
D. can’t
This cake is very sweet. You ___ a lot
of sugar in it.
A
. Should put
B. could have
put
C. might put
D. must have put
I was on the highway when this car went
past followed by a police car. They ___
at least 150 kilometers an hour.
A. should have been doing
B.
must have been doing
C.
could have done
D.
would have done
I didn’t
hear the phone. I ____ asleep.
A. must be
B.
must have been
C. should be
D. should have been
2.
may/ might
have done
也用于对已经发生过的情况的肯定推测判断,但语气
稍弱,意思是“可能,或许??”。例如: