对情态动词表示推测的用法，是高考考查情态动词的一个重要方面。例如：
Sorry, Im I______have turned off the alarm clock and gone back to sleep again .
might should can will
解析：might have done : (过去)可能做过某事;shouldhave done :本应该做某事。根据本句提供的情境Im late 表明说话人可能把闹钟关上了。答案是：A。
分析：高考对表示推测的情态动词集中在must, can, could, may, might上，准确掌握它们使用的场合，是解决问题的关键。Must 用于肯定陈述句，表示肯定推测;can, could用于疑问或否定陈述句，表示可能性推测;may, might用于陈述句，表示可能性推测;用于否定陈述句中，cant (不可能)的语气比may not(可能不)强。此外，还要注意有对过去和对现在两种情况的推测,对过去推测用情态动词+have done ，对现在推测用情态动词+ 动词原形。
在含有表示坚持、建议、命令、要求等含义的名词性从句和在it做形式宾语或形式主语的复合句中，宾语补足语是necessary/strange/essential/natural/a pity/a shame等表示惊奇、惋惜或者理应如此等含义时，从句中的谓语动词需用should+动词原形，其中should可以省略。例如：
Dont you think it necessary that he ______ to Miami but to New York?
I agree，but the problem is ______ he has refused
not be sent;that be sent;that
not be sent;what not send;what
解析 问句句意为：难道你不认为必须把他送到迈阿密而不是纽约吗?句子表示理应如此的意思。正确答案为B。
与现在事实相反的虚拟语气，基本结构为：主语+动词的一般过去时(be动词用were)+其他成分+if++动词原形+其他成分。例如：
①If it were not for the fact that she ______ sing，I would invite her to the
not
解析 句意为：如果不是因为她不会唱歌的事实，我会邀请她来参加那次聚会的。that从句为同位语从句，描述的是事实，用陈述语气。正确答案为C。
与过去事实相反的虚拟语气，基本结构为：主语+动词的过去完成时+其他成分+if++have done+其他成分。例如：
If the weather had been better，we could have had a it ______ all
rained raining
解析 句意为：如果天气好的话，我们是能够去野餐的，但是下了一天的雨。句子前半部分陈述的是与过去事实相反的事情，所以用了虚拟语气。下了一天的雨是事实，所以用陈述语气。因为是发生在过去的事实，所以正确答案为A。
与将来事实相反的虚拟语气，基本结构为：主语+动词的一般过去时/should do/were to do+其他成分+if++动词原形+其他成分。例如：
If I ______ plan to do anything I want to，Id like to go to Tibet and travel through as much of it as
to to
解析 句意为：如果我能够计划做我想做的事情，我想去西藏并且尽可能多玩一些地方。句子描述的是与将来事实相反的事情，所以正确答案为B。
这样的虚拟句不含有if从句，而是以but for/without/or/otherwise等引导的句子代替if从句，主句的谓语动词的形式与前面虚拟语气的基本用法相同。例如：
Thank you for all your hard work last dont think we ______ it without
manage have managed
managed have managed
解析 由语境可知这里要表达的意思是：如果没有你们辛勤的工作，我们不可能处理好这件事。很显然，这是对过去发生的事实的虚拟，所以要用could have done，故应选B。
在有些虚拟条件句中，主从句时间不一致，应根据不同情况区别对待。例如：
Its hard for me to imagine what I would be doing today if I ______ in love，at the age of seven，with the Melinda Cox Library in my
have fallen not fallen
fall to fall
解析 句意为：如果不是我在七岁时爱上家乡的Melinda Cox图书馆的话，很难想象今天的我会是什么样子。主句描述的是与现在事实相反的事情，从句描述的是与过去事实相反的事情。正确答案为B。
在含有表示坚持、建议、命令、要求等含义的名词性从句和在it做形式宾语或形式主语的复合句中，宾语补足语是necessary/strange/essential/natural/a pity/a shame等表示惊奇、惋惜或者理应如此等含义时，从句中的谓语动词需用should+动词原形，其中should可以省略。例如：
Dont you think it necessary that he ______ to Miami but to New York?
I agree，but the problem is ______ he has refused
not be sent;that be sent;that
not be sent;what not send;what
解析 问句句意为：难道你不认为必须把他送到迈阿密而不是纽约吗?句子表示理应如此的意思。正确答案为B。
情态动词+have+过去分词表示与过去事实上相反的情况，也是高考单项选择题涉及到情态动词的一个重要方面。
There was a lot of fun at yesterdays You______come, but why didnt you?
must have should
need have ought to have
解析：ought to have done 表示本来应该做某事而实际没做，should do 表示现在应该做某事，与题中 at yesterdays party 表示的时间不一致。所以选D。
分析：高考对情态动词表示虚拟用法，表示与过去事实相反的情况。近几年高考，主要侧重should (not)have done 这一句式上，表示本来不该做却做了或本来该做却未做的事，在复习时，还应关注其它几种虚拟形式，如need (not)have done 表示本来需要做而未做或本来不需要而做的事等等，以做到有备无患。
考点四、情态动词与助动词混合考查
,you didnt come to the party last night?
I______, but I suddenly remembered I had homework to do .
had to didnt was going to wouldnt
解析：had to:不得不;didnt:没来;was going to：打算来;wouldnt:不愿来。句意：汤姆，昨晚你没来参加舞会吗?我本打算来，但我突然记起有作业要做。But是关键词，所以答案是：C。
phone number again? I______quite catch it .
Its
didnt couldnt dont cant
解析：记住电话号码并非难事，未完全听清楚电话号码并非能力的事，此处只是说没有完全听清楚电话号码，所以，应选A。
【精选试题】 名校模拟题及其答案
I still havent thanked Aunt Lucy for her Its time you
do did had would
If I hadnt been lucky enough to meet I really _____ what I would have
dont know hadnt known
wasnt knowing wouldnt know
Ive told everyone about Oh, Id rather you
dont hadnt
couldnt wouldnt
It has been raining for a day, but eventhough it hadnt rained, we _____ there by
cant get wont get
hadnt got wouldnt get
Do you know his address? No, I also wish I _____ where he
knew, live knew, lives
know, lives know, lived
Isnt it about time you _____ to do morning exercises? Yes, it Would you like to join us?
begin have begun
began had begun
It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my
wouldnt have fallen had not fallen
should fall were to fall
He hesitated for a moment before kicking the ball, otherwise he ____ a
had scored scored
would score would have scored
If only he _______ quietly as the doctor instructed, he would not suffer so much
lies lay
had lain should lie
Without the air to hold some of the sunsheat, the earth at night ____ for us to
would be freezing cold will be freezing coldly
would be frozen cold can freeze coldly
I forget where I read the article, or I _____ it to you
will show would show am going to show am showing
It looks as if he were So it
Hed better give up drinking
He shouldnt have drunk so much
Health is more important than drink
I wonder why he is always doing so
Mary looks hot and dry So _____ you if you had so high a
do are will would
He will come But Id rather he _____ the day after
will come is coming
came had come
All the doctors in the hospital insisted that he ____ badly wounded and that he ____ at
should be; be operated on
were; must be operated on
was; should be operated
was; be operated on
______ smoking, he would not have got cancer in the
Was he given up Had he given up
Did he give If he gave up
I still havent thanked Aunt Lucy for her Its time you
do did had would
Do you know his address? No, I also wish I _____ where he
knew, live knew, lives
know, lives know, lived
It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my
wouldnt have fallen had not fallen
should fall were to fall
Without the air to hold some of the suns heat, the earth at night ____ for us to
would be freezing cold will be freezing coldly
would be frozen cold can freeze coldly
fired, your health care and other benefits will not be immediately cut
Would you be Should you be
Could you be Might you be
cant imagine that a well-behaved gentleman _____ be so rude to a
might need should would
But I want to use your computer to type a
You _____have my computer if you dont take care of it .
shant might not neednt shouldnt
He _____ have completed his work; otherwise, he wouldnt be enjoying himself by the
should must wouldnt cant
I ______ have been more than six years old when the accident
shouldnt couldnt mustnt neednt
There _____ be any difficulty about passing the road test since you have practiced a lot in the driving
mustnt shant shouldnt neednt
I was on the highway when this car went past Lowed by a police They ______ at least 150 kilometers an
should have been doing must have been doing
could have done would have done
Ive taken someone elses green sweater by
It ______ He always wears
has to be will be mustnt be could be
Catherine, I have cleaned the room for
You ______ I could manage it
neednt do neednt have done
mustnt do shouldnt have done
Lucy doesnt mind lending you her
She Ive already borrowed
cant mustnt neednt shouldnt
【答案与解析】
【解析】选 time you did 为 Its time you thanked Aunt Lucy for her present 之略。按照英语语法，its time 后从句通常要用过去式。
【解析】选虽然前有虚拟条件句, 后有使用了虚拟语气的宾语，但 I dont know 却宜用一般现在时，因为 I dont know 表述的是现在的真实情况，句意为我要不是有幸遇到你，我真不知(指现在不知)我会做出什么蠢事来。
【解析】选 rather 后接从句时，从句谓语的时态规律是：用过去式表示现在或将来，用过去完成式表示过去。
【解析】选 cant get there by tomorrow 为客观事实，故宜用陈述语气。
【解析】选第一空填 knew，因为 I wish 后的宾语从句要用虚拟语气(即用过去式表示现在的想法);第二空要填lives，即用陈述语气，因为 where he lives 是一个客观事实，而不是 I wish 的内容。
【解析】选 time / Its high time / Its about time 等后接从句时，从句谓语通常用过去式。
【解析】选 此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。句意为：要不是在七岁时就迷上了 Melinda Cox 图书馆，我真不能想像我如今会在做什么。
【解析】 选 这是otherwise 引出的含蓄虚拟语气，再根据前面的 hesitated 可进一步知道这是与过去事实相反的虚拟语气，由此可推知答案选
【解析】选 only意为要是就好了，其后的句子谓语要用虚拟语气，同时根据 as the doctor instructed 中的过去时态可知从句是与过去事实相反，故选
【解析】选 引出的介词短语为一个与现在事实相反的含蓄条件句。
【答案】C
【解析】.根据上文的语境可知句中的 or 隐含有一个虚拟的条件，即 or=if I didnt forget where I read the article(要是我没忘记我在哪儿读过这篇文章的话但事实上忘了)。
【答案】B
【解析】关键信息是It looks as if he were drunk 中的虚拟语气，句子既然用了虚拟语气，也就是说，他喝醉了不是事实，只是他的言行好像是醉了，所以此题的最佳答案是
【答案】
【解析】 由于空格后的 if 条件状语从句的谓语用的是虚拟语气(这是很重要的信息)，所以主句要用 would 而不用 will，即答案应选
【答案】D
【解析】按照英语习惯，would rather 后接that 从句时，从句谓语通常要用虚拟语气，即用过去式表示现在或将来， 用过去完成时表示过去。
【答案】C
【解析】insist后的从句谓语有时用should+动词原形这样的虚拟语气，有时不用，具体要看该谓语动词所表示的含义。一般说来，若该谓语动词所表示的动作尚未发生，或尚未成为事实，则用虚拟语气;若该谓语动词所表示的动作已经发生，或已经成为事实，则要用陈述语气。分析上题的句意，可知只有选D最合适。
【答案】D
【解析】是因为时态前后有矛盾。由于主句谓语是would not have got，这表明是对过去事实作出的假设，所以从句谓语应该是 had given up，而不是像D项那样用一般过去时。另外，当虚拟条件句中有 had, should, were 等词时，通常可以省略 if，并将 had, should, were 提前置于句首。
【答案】B
【解析】Its time you did 为 Its time you thanked Aunt Lucy for her present 之略。按照英语语法，its time 后从句通常要用过去式。
【答案】B
【解析】第一空填 knew，因为 I wish 后的宾语从句要用虚拟语气(即用过去式表示现在的想法);第二空要填lives，即用陈述语气，因为 where he lives 是一个客观事实，而不是 I wish 的内容。
【答案】B
【解析】 此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。句意为：要不是在七岁时就迷上了 Melinda Cox 图书馆，我真不能想像我如今会在做什么。
【答案】B
【解析】without 引出的介词短语为一个与现在事实相反的含蓄条件句。
【答案】A
【解析】句意：万一你被解雇，给你的医疗救助和其它方面的福利也不会被取消。
【答案】B
【解析】句意：你想象不到这么一个表现良好的绅士竟然会对一个女士这么粗鲁。
【答案】C
【解析】shall此处表示警告。
【答案】A
【解析】B此处考查情态动词表示推测的用法。should have done表示过去应该做而实际并没有做，因此淘汰A项。would不用来表推测，因此淘汰C项。B基与D项虽然都可以表示推测，但B项表肯定意义而D项表示否定推测，意为不可能，根据句意：他肯定已完成了他的工作;不然，他就不会在海边玩得那么愉快了。可知此处需要肯定意义，因此淘汰D项。
【解析】B本题考查情态动词的用法。must表示推测只能用于肯定句，否定句用can或could 代替。shouldnt have done 表示本来不该而实际上却做了某事.neednt have done表示本来不必而实际上却做了均不合题意。本句的意思是：当事故发生时我不可能超过6岁。
【解析】C should(按道理)应该;句意：既然你在驾校时做了大量练习，那么通过这次考试理不应该有困难。
【解析】B 第一句话使用了一般过去时，由此可知第二句话是对过去事情的猜测，需用must have 本题意为我正在高速公路上行驶，这时一辆警车跟随着着这辆车从旁边经过。它们一定是以至少每小时150公里的速度行驶。故选B。A项表示本应该，C项表示本能够不合题意。
【解析】D 本题考查情态动词的用法。句意是我错拿了别人的绿色 毛衣，那可能是Harry的，他总是穿绿色的毛衣。四个选项中could表示推测。mustnt 表示 禁止has to 表示不得不will 表推测时，表肯定语气太强。
【解析】B根据句意可知Catherine对对方为她打扫了房间表示感谢并提到对方本来不必为她打扫房间。很显然对方打扫房间是过去所为，表达去不必做某事用neednt have done
【解析】C本题考查情态动词，从答语的后半句我已经借到一本字典了，可知前半句为不必了。故C正确。
【微语】真正的史笔，不是史官手中的毛笔，而是人心。
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