情态动词有没有虚拟语气
- 提问者网友：姑娘长的好罪过
- 2021-01-24 22:46
- 五星知识达人网友：神的生死簿
- 2021-01-25 00:14
cannot+ have done：表示对现在或过去行为的否定推测.He cannot have been to that town.
can+主语+ have done：表示对过去行为的怀疑或不肯定（用在疑问句中）.Can he have got the book?
might(may)+ have done：对过去发生的行为不太肯定的推测.He may not have finished the work.
If we had taken the other road, we might have arrived earlier.
must+ have done：对过去发生的行为肯定的推测.
其否定式为：cannot have done.You must have seen the film.
You cannot have seen the film.
needn’t+ have done：本来不必要做的而实际上又做了.You needn’t have watered the flowers,for it is going to rain.
注意：didn’t need to(have to)do：
没有必要做而实际上也没有做
I didn’t need to clean the windows.My sister did it 2 hours ago.
should(ought to)+ have done：本来应该做而实际上又没有做.其否定形式表示某中行为不该发生却发生了.You should have started earlier, but you didn’t.
She shouldn’t have taken away my measuring tape,
for I worked to use it.
注意：He should have finished the work by now.（表推测）
虚拟语气
类 别用 法例 句
If引导的
条件从句与现在事实相反从句动词：过去式（be用were）
主句动词：should/would/could/might+doIf he were here, he would help us.
与过去事实相反从句动词：had+done
主句动词：should/would/could/might+have+doneIf I had been free,I would have visited you.
与将来事实相反从句动词：过去式/should+动词原形/were+to do
主句动词：should/would/could/might+动词原形If it should rain tomorrow, we would not go camping.
省略if的虚拟条件句将虚拟条件从句中的were,had,should放到主语之前,构成主谓倒装①Should he come ,tell him to ring me up.
②Were I you,I would not do it.
③Had I been free,I would have visited you.
混合虚拟条件句不同时间的虚拟：各遵守各的规则①If he had listened to me, he would not be in trouble now.
②If he had told me yesterday,I should know what to do now.
③If I were you, I would have gone to her birthday party.
虚拟与陈述的混合：各遵守各的规则①He could have passed the exam,but he wasn’t careful enough.
②You should have come earlier.The bus left a moment ago.
含蓄虚拟
条件句but for+名词表示虚拟条件句子或主句中的谓语动词的形式视具体情况而定.这是考查考生应变能力的最佳试题.---But for your timely warning,we ______ into great trouble.
---You know we’re friends.
A. would get B. must have got
C. would have got D. can’t have got
without+名词表示虚拟条件Without the air to hold some of the sun's heat, the earth at night would be freezing cold.
动词不定式表示虚拟条件It would be only partly right to follow in this way.
如果用这种方式,仅仅对了一半.
现在分词表示虚拟条件Having known in time ,we might have prevented the accident.要是及时得知的话,我们也许能阻止这场事故.
过去分词表示虚拟条件Given more attention, the tree could have grown better.
如果多留心的话,这树本来可以长的更好.
副词otherwise表示虚拟条件I was too busy at that time.Otherwise,I would have called you.我当时太忙,否则我就给你打电话了.
连词but连接的句子表示虚拟条件He _____fatter but he eats too little .
A. would become B. would have become
C. must become D. must have become
其它
状语从句as if/as though引导的状语从句中动词用did或had＋done或would／could／might＋do.
注意：as if/as though引导的状语从句中也可以用陈述语气：
当说话者认为所述的是真实的或极有可能发生或存在的事实时：
It sounds as if it is raining．听起来像是在下雨.
He talks as if he is drunk．从他谈话的样子来看他是醉了.①与现在事实相反
He talks as if he knew where she was．
②与过去事实相反
He talks about Rome as if he had been there before.
③与将来事实相反
He opened his mouth as if he would say something.
in order that/so that引导的状语从句中动词用can/could/may/ might/ would等+doTurn on the light so that we can see it clearly.
宾语从句demand, suggest, order, insist后接的从句中动词为should+doHe suggested that we not change our mind.
wish后的从句中分别用过去式,过去完成式和should/would+do表示与现在,过去和将来情况相反I wish I could be a pop singer.
I wish I would have gone to Shanghai last month.
主语从句在It is necessary / important / strange that…
It is suggested / demanded/ ordered / requested that…等从句中,
谓语动词用should+doIt is strange that such a person should be our friends.
其它
句型中It is time that…句型中动词用过去式或should+doIt’s high time that we left/should leave.
would rather所接的从句中动词用过去式或者过去完成式I would rather you stayed at home now.
If only句型中动词常用过去式或者过去完成式,表示强烈的愿望If only our dream had come true!
- 1楼网友：琴狂剑也妄
- 2021-01-25 00:34
情态动词can, may, must, need, shall, should, will, would
can, can’t / cannot, -- could
1.表示具有某种能力，“能，会”。 can you come this evening?
2. 表示可能性，“可以，可能”。 i think we can find a good way.
3. 表示许可，“可以” 在口语中可用may代替。you can / may go now.
4. 口语中常用could代替 can 表示有礼貌，不表示过去。
could i use your dictionary?
be able to “能，会”，有多种时态，可表示将来具有的能力。can通常指本身具有的能力。
if he becomes a professional athlete, he won’t be able to go to college.
the child has been able to read story books since last year.
andrew can speak a little chinese now.
may, may not, --might
1．用来征求对方意见，“允许，可以”。 may i open the window?
2．表示猜测和判断，“可能，也许”. the woman may be 40.
3．may 用于否定句时，may not“可能不” she may not know the owner.
4．用于祈使句中，“祝愿，希望” may you be happy.
might
1. 用来表示过去的“可能”、“允许”，多用于间接引语。
he said that i might use his telephone.
she was afraid they might not like her idea.
2. 表示现在的“可能”“允许”，即表示现在可以做的事或可能发生的事，这时might 不是may 的过去式，两者表示的时间一样，只是用 might时语气比较婉转或实现的可能性更小一些。
he might be an englishman. they might have a lot of work to do.
might i have a word with you? i wonder if i might borrow your dictionary.
must, mustn’t, --must
1.表示说话的主观意志，“必须，应该”。否定式回答用needn’t 或don’t have to。 must i clean the room? – no. you needn’t.
2. must本身的否定形式 must not 意为“不准”，表示禁止，告诫。
you mustn’t play on the road.
3. 表示对事物的推测，“想必，一定”，只用于肯定句中，有把握的否定判断用can’t。 he must be in the classroom now. he can’t at home.
have to/ has to 强调客观需要。“必须，不得不” 强调说话者的主观看法。
he has to stay at home and look after his mother. his mother is ill.
you don’t have to finish the work at once. you can finish it tomorrow.
we must go to school on time every day.
need 一般只用于疑问句和否定句中，其否定形式是needn’t，后跟动词原形。由need 引起的一般疑问句中，其肯定回答用must ，否定回答用needn’t.
you needn’t give it back today.
-need i go there, too? - yes, you must. / no, you needn’t.
shall, shan’t -- should. should 表示劝告或建议。shall做情态动词常用于一般疑问句，与第一人称连用，表示征求意见。
you should go to see the doctor.
shall we meet at six tomorrow?
will, won’t. – would 作情态动词时，常用来表示意愿，请求等。
will you please go with me?
常用来表示意愿、请求。比语气更委婉。
would you please open the window?
ought to, ought not to/ oughtn’t to
1. 表示义务，“应该”，语气比should重，但比 must更委婉。
2. 表示推测，“可能”，语气比must弱，没 must那么肯定。
you don’t look well. you ought to go to see the doctor.
you ought not to write so carelessly.
oughtn’t we to give him a chance to try?
虚拟语气
虚拟语气表示说话人的愿望、假设、猜测或建议，不是表示客观存在的事实。虚拟语气是通过句中谓语动词的特殊形式来表示的。
（一）虚拟语气在简单句中的用法
虚拟语气用于简单句中，一般表示祝愿、命令等，谓语动词用原形。
long live the peace! 和平万岁！ may you succeed! 祝你成功！ (may用于句首表祝愿) may you be happy all your life! 祝你一生幸福！
(二)虚拟语气在条件句中的用法
虚拟语气条件句是用谓语动词的特殊形式来表示与现在、过去事实相反的情况或对将来发生的情况表示怀疑。虚拟语气条件句中所用的谓语动词的过去时、过去完成时、过去将来时等只表示不同的虚拟语气，与陈述语气句子的过去时、过去完成时等毫无关系。
1．表示与现在事实相反的情况
| 条件从句的谓语动词 | 主句的谓语动词 |
| 动词过去式（be一般用were） | should / would+动词原形 |
如果我有更多的时间，我就学日语。
if i _____ more time, i would study japanese.
= i don’t have more time now, so i don’t study japanese.
要是她不那么忙，她就和我一起来来这里了。
if she _______ not so busy, she _______ _______ here with me.
= she is very busy, she can’t come here.
如果你早点睡觉，早晨就不会这么困了。
if you went to bed earlier, you ______ ________ so sleepy in the morning.
= you often go to bed late, so you are sleepy in the morning.
2. 表示与过去事实相反的情况
| 条件从句的谓语动词 | 主句的谓语动词 |
| had + 动词过去分词 | should/ would + have + 动词过去分词 |
昨天我身上有钱，我就买那本故事书了。
i would have buy the story-book if i had had money with me yesterday.
= i had no money yesterday, so i didn’t buy the book.
如果你早用功，你就不至于考试不及格了。
if you had worked hard, you wouldn’t have failed the exam.
= you didn’t work hard, so you didn’t pass the exam.
假如他及时完成了作业，他早就上床睡觉了。
he would have gone to the bed if he had finished doing his homework in time.
= he didn’t finish homework in time, so he didn’t go to bed.
1． 表示与将来事实相反的情况
| 条件从句的谓语动词 | 主句的谓语动词 |
| 1．动词过去式 2．should + 动词原形 3．were to+ 动词原形 | should/ would + 动词原形 |
如果明天天下雨，我们的野餐就推迟。
if it rained tomorrow, our picnic would be put off.
= it is fine recently, it is impossible to rain.
万一明天你迟到了，我们就不等你了。
if you should be late tomorrow, we wouldn’t wait for you.
假如明天我能看见他，我就把你的便条给他。
if i were to see him tomorrow, i could/ should pass your note to him.