高中情态动词大全PPT课件
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【高中语法复习】情态动词(共48张PPT)
need to do
need do
Need 的回答
Need I come here tomorrow ？ Yes, you must.
No, you needn’t. / you don’t have to.
Johnny, you ____ play with the knife, or you ____ hurt yourself.
猜测
--Oh my god ! Can it be true ? --It can’t be ture.
常用词组积累 can not/ never…too; can’t…enough
can’t help doing
无论怎么…都不过分 禁不住；不由得
I could have worked out the question, but I was too nervous.(过去有能力做但未做)
I must take care of my hairstyle.
must 的回答
-不用mustn’t回答-
Must I go to school today?
Yes,you must !
No, you don’t have to. /needn’t. /had better not.
You mustn’t bully your brother. He must have seen the answer.
时态 单复数 肯定变否定
提问
3
情感和态度
can
could may
might must should
情态动词 情态实意
must, can, could, may, might, ought stohall, should, will, would
need do
Need 的回答
Need I come here tomorrow ？ Yes, you must.
No, you needn’t. / you don’t have to.
Johnny, you ____ play with the knife, or you ____ hurt yourself.
猜测
--Oh my god ! Can it be true ? --It can’t be ture.
常用词组积累 can not/ never…too; can’t…enough
can’t help doing
无论怎么…都不过分 禁不住；不由得
I could have worked out the question, but I was too nervous.(过去有能力做但未做)
I must take care of my hairstyle.
must 的回答
-不用mustn’t回答-
Must I go to school today?
Yes,you must !
No, you don’t have to. /needn’t. /had better not.
You mustn’t bully your brother. He must have seen the answer.
时态 单复数 肯定变否定
提问
3
情感和态度
can
could may
might must should
情态动词 情态实意
must, can, could, may, might, ought stohall, should, will, would
高中英语 情态动词用法归纳全.ppt
情态动词用法归纳
情态动词无人称和数的变化；不能单独 使用，必须与其后的动词原形构成谓语
一、 can, could
1) 表示能力（体力、知识、技能）。 Can you lift this heavy box?（体力） Mary can speak three languages.（知识） Can you skate?（技能） 此时可用be able to代替。 Can只有一般现在时和一般过去式；而be able to则有
2. He doesn’t dare (to) answer.
3. He needs to finish his homework today.
五、 shall, should
1) shall 用于第一人称，征求对方的意见。
What shall we do this evening?
2) shall 用于第二、三人称，表示说话人给对方的命令、警告、 允诺或威胁。
七、should, ought to
1) should, ought to表示“应该”，ought to表示义务或责任， 比should语气重。
1. I should help her because she is in trouble.
2. You ought to take care of the baby.
1. You shall fail if you don’t work hard.(警告) 2. He shall have the book when I finish it.(允诺) 3. He shall be punished.(威胁)
六、 will, would
1) 表示请求、建议等，would更委婉。 Will / Would you pass me the ball, please? 2) 表示意志、愿望和决心。 1. I will never do that again. 2. They asked him if he would go abroad.
情态动词无人称和数的变化；不能单独 使用，必须与其后的动词原形构成谓语
一、 can, could
1) 表示能力（体力、知识、技能）。 Can you lift this heavy box?（体力） Mary can speak three languages.（知识） Can you skate?（技能） 此时可用be able to代替。 Can只有一般现在时和一般过去式；而be able to则有
2. He doesn’t dare (to) answer.
3. He needs to finish his homework today.
五、 shall, should
1) shall 用于第一人称，征求对方的意见。
What shall we do this evening?
2) shall 用于第二、三人称，表示说话人给对方的命令、警告、 允诺或威胁。
七、should, ought to
1) should, ought to表示“应该”，ought to表示义务或责任， 比should语气重。
1. I should help her because she is in trouble.
2. You ought to take care of the baby.
1. You shall fail if you don’t work hard.(警告) 2. He shall have the book when I finish it.(允诺) 3. He shall be punished.(威胁)
六、 will, would
1) 表示请求、建议等，would更委婉。 Will / Would you pass me the ball, please? 2) 表示意志、愿望和决心。 1. I will never do that again. 2. They asked him if he would go abroad.
高中英语情态动词课件精品
couldn’t be a doctor.
B. could可以代替can表示请求、“允许
”。可表示委婉客气的提出问题或陈述
看法
Could you lend me your dictionary? Could I use your bike? Yes, you can. I’m afraid I couldn’t give you an answer today.
意愿“要；愿”
Would 与 Used to do 区别 ——— “过去常常”
Would
------过去习惯的动作（现在有可能还有此习惯）
Used to do
--------过去习惯的动作及状态（现在已经没有此习惯）
e.g. He would get up at 8 a.m. (现在有可能还在坚持此习惯) e.g. He used to get up at 8 a.m. （现在已经不再坚持此习惯）
动作
e.g. There used to be an old building
here when I was young.
状态
shall和should：
1. shall用于构成将来时是助动词。 shall用于征求对方的意见，表示 “决心” 是情态动词。 eg: Perhaps I shall pay a visit to England this winter. 可能今年冬天我会去英国观光。 （构成一般将来时, 助动词）
3)表示请求或允许(和may意思相近)常见于 口语。 Can (May) I come in ? 我能进来吗? Can I smoke here ? 我可以在这里抽烟吗?
2) could的主要用法是： A. could 是can的过去式, 表示与过去 有关的能力和推测:
B. could可以代替can表示请求、“允许
”。可表示委婉客气的提出问题或陈述
看法
Could you lend me your dictionary? Could I use your bike? Yes, you can. I’m afraid I couldn’t give you an answer today.
意愿“要；愿”
Would 与 Used to do 区别 ——— “过去常常”
Would
------过去习惯的动作（现在有可能还有此习惯）
Used to do
--------过去习惯的动作及状态（现在已经没有此习惯）
e.g. He would get up at 8 a.m. (现在有可能还在坚持此习惯) e.g. He used to get up at 8 a.m. （现在已经不再坚持此习惯）
动作
e.g. There used to be an old building
here when I was young.
状态
shall和should：
1. shall用于构成将来时是助动词。 shall用于征求对方的意见，表示 “决心” 是情态动词。 eg: Perhaps I shall pay a visit to England this winter. 可能今年冬天我会去英国观光。 （构成一般将来时, 助动词）
3)表示请求或允许(和may意思相近)常见于 口语。 Can (May) I come in ? 我能进来吗? Can I smoke here ? 我可以在这里抽烟吗?
2) could的主要用法是： A. could 是can的过去式, 表示与过去 有关的能力和推测:
《高中情态动词》课件
常用情态动词：need to
情态动词need to表示需要和必须。它常用于表示某人需要做某事或某事必须 发生的情况。
常用情态动词：have to
情态动词have to表示必须和不得不。它常用于表示某事必须发生，或者表示强奸的义务和责任。
常用情态动词：dare to
情态动词dare to表示敢于、冒险和挑战。它常用于表示敢于做某事或挑战某种观念或权威。
常见用法和例
表达能力
He can swim across the rivmorrow.
提出建议
You should study harder for the exam.
表达许可
Can I go to the party?
表示义务
I must finish my homework before I can watch TV.
常用情态动词：could
情态动词could用于表示过去的能力、许可和可能性。它可以表达过去某一时刻的能力和可能性，也可 以用于客气地请求许可。
常用情态动词：may
情态动词may表示许可、可能性和推测。它常用于礼貌地请求许可，也可以表示某事可能发生或猜测。
常用情态动词：might
情态动词might用于表示可能性、推测和建议。它常用于表示某事可能发生或猜测，也可以用于委婉地 提出建议。
情态动词的种类和区别
常见的情态动词包括can、could、may、might、will、would、should、must、 shall、ought to、need to和have to等。每个情态动词都有自己独特的用法和 意义，需要根据具体语境来理解和运用。
常用情态动词：can
情态动词can表示能力、许可和可能性。它常用于表达一个人有能力做某事， 或某事可能发生的情况。
情态动词语法讲解PPT课件
2表示“许可”和“不许”
a)请求对方“许可”可用can, could, may, might.
may/might较正式，could/might较委婉
表示给予“许可”通常用can/may,而不用 could/might
Could I use your phone? Yes, of course you can. Might I trouble you for a light? You may indeed.
表示将来的“必须”，常用have to的一定 形式（will/shall have to) 比较：
•We must do it again.(表示现在)
•We’ll have to do it again.(表示将来)
•表示过去的“必须”，常用had to
•I had to leave at six yesterday.
•They must be home by now.（他们现在一定到家了）
will/would表示“推测”可有三种情况
1）对特定事态的推测
A: Who’s that man over there? B: That will be George, no doubt. C: That would be George, I except.
• Can they have missed the bus?
• Yes, they may have.
may not重音落在助动词上，表示 “不可能”，重音落在否定词上，表 示“不许可” , 比较：
•He may not go tomorrow.
•He may not go tomorrow.
•所以在书面语中，表示“不可能” 常用can’t
高中英语情态动词精品PPT课件
— Might I watch TV after supper? — Yes, you ________. A. may B. must C. might D. could
.
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3.表推测，表示主观上的推测，“可能，
也许”，不用于疑问句, might比
may的可能性更小
She may not like this place.
—Yes, he _______. A. need B. must C. may D. will
.
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2. must表示肯定的推测。 The light is still on, so he must be at home.
Look at his new car. He ______ have a lot of money. A. should B. shall C. may D. must
I can’t believe my eyes. Such well-educated
gentleman ____ behave like this!
A.will B. would C. should D. must
What time ought I _______?
A．arrived
B．arriving
C．arrive
D．to arrive
He _______ speak to his mother like that. A．ought not to B．doesn’t ought to C．not ought to D．ought to not
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1. should= ought to 表示劝告，建议，意 为“应该”， ought to 语气更强些，强调“有责任，有 义务做”
《英语情态动词》PPT课件
(12) You can't be too careful while driving. 开车时越小心越好。
【结论6】 cannot ... too/enough表示“无论……也不过 分”；“越……越好”。用来加强语气。 (13) I couldn't but choose to wait.
【结论7】cannot but do sth. 不得不；只好 (14) They were able to put out the fire without any help from the firefighters.
(8) Can it be true? (9) You can't be serious! (10) Oh, dear, what on earth can this mean? (11) How could you do such a silly thing? 你怎么能做那样的蠢事呢？ 【结论5】表示惊讶、怀疑、不相信的态度，常用在否 定句、疑问句和感叹句中。
(3)表示“偏执”，“固执” “偏要、硬要” 。 — How old are you, madam? — If you must know, I'm twice my son's age. Don't interrupt me, John. Must you force me to tell you the truth at the moment?
A computer can’t think for itself; it must be told what to do.（一般能力） 句意为：对绝大多数受到威胁时而不能起身逃跑的植物 He is a native speaker of English, so he can of course 来说，最大的问题是动物喜欢吃它们。情态动词can 可 speak English quite well.（一般能力） 表示对能力的否定。 I以表示人的能力和物的性能，故选 am starving to death. I can eat twoB bowls of rice now. （现在的能力） The biggest problem for most plants, which ___just get up and run away when threatened, is that animals like to eat them.(07湖南) A. shan’t B. B can’t C. needn’t D. mustn’t
情态动词精品课件PPT课件
第22页/共52页
• It is usually warm in my hometown in March，but it can be rather cold sometimes.
• 我的家乡在三月份通常很暖和，但有时候也会相当冷。 • Mr.Bush is on time for ever ything.How can it be that he was late for the
meeting? • 布什先生做什么事情都很准时，他怎么可能开会迟到呢？ • He can't be in the classroom ，for the light has been turned off. • 他一定不在教室里，因为灯已关了。
第23页/共52页
• 2．may用于肯定句中可以用来表示推测，意为“可能”；用于否定句中也可以表示 推测，may not意为“可能不”，表示一种不太确定的语气。may在疑问句中一般不 表示推测。
You'd better not. 等)不，你不可以用。
第11页/共52页
• 3．must和have to的用法 • must表示“必须、应该”。否定形式must not(mustn't)表示“不应该、不许可、
不准、禁止”等。在回答must的问句时，否定式常用need not(needn't)或don't have to表示“不必”，而不用must not，因为must not表示“禁止”。must表 示“一定、必定”等推测意义时，一般只用在肯定句中。 • The work must be finished as soon as possible. • 这项工作必须尽快完工。
第21页/共52页
• 热点考向二 情态动词表“推测”的用法 • 表示对目前或将来情况的推测往往用“情态动词＋动词原形”这种结构。 • 1．can用于肯定句中表示可能性，意为“有时会”；用于疑问句中可以表示推测，意
• It is usually warm in my hometown in March，but it can be rather cold sometimes.
• 我的家乡在三月份通常很暖和，但有时候也会相当冷。 • Mr.Bush is on time for ever ything.How can it be that he was late for the
meeting? • 布什先生做什么事情都很准时，他怎么可能开会迟到呢？ • He can't be in the classroom ，for the light has been turned off. • 他一定不在教室里，因为灯已关了。
第23页/共52页
• 2．may用于肯定句中可以用来表示推测，意为“可能”；用于否定句中也可以表示 推测，may not意为“可能不”，表示一种不太确定的语气。may在疑问句中一般不 表示推测。
You'd better not. 等)不，你不可以用。
第11页/共52页
• 3．must和have to的用法 • must表示“必须、应该”。否定形式must not(mustn't)表示“不应该、不许可、
不准、禁止”等。在回答must的问句时，否定式常用need not(needn't)或don't have to表示“不必”，而不用must not，因为must not表示“禁止”。must表 示“一定、必定”等推测意义时，一般只用在肯定句中。 • The work must be finished as soon as possible. • 这项工作必须尽快完工。
第21页/共52页
• 热点考向二 情态动词表“推测”的用法 • 表示对目前或将来情况的推测往往用“情态动词＋动词原形”这种结构。 • 1．can用于肯定句中表示可能性，意为“有时会”；用于疑问句中可以表示推测，意
情态动词(共43张PPT)
A．Must; mustn't
B．Will; couldn't
C．May; can't
( C ) It's really hot in the room.You'd better
the
windows. A．not to close B．don't close C．not close
(B )
—You
drive after drinking, Simon.
—You're right.I'll take a taxi.
A．wouldn't B．shouldn't C．ought to
二、用恰当的情态动词填空。
Simon, you mmuussttnn''tt play with the knife.You mmayay
在回答以 may 提问的问句时，肯定回答一般可仍用 may 或 Yes, please./Certainly./Sure./Of course.否定回答根据说话人的语气 由强到弱分别选用： mustn't/can't/may not。 —May I watch TV? 我能看电视吗？ —No, you mustn't.You must play the piano first.不，你禁止看， 你必须先弹钢琴。
need 的基本用法 意为“需要；必要”，作情态动词时常用于否定句和疑问句中。 You needn't hand in your homework tomorrow.你明天不需要 交你的作业。 Need I attend the meeting this afternoon? 我需要今天下午参 加会议吗？
高中英语情态动词各种用法课件(共47张PPT)
一 、表能力 ：表现在的或一般的能力：表示 现在的或一般的能力用can 或 be able to. 一 般的能力是指你无论什么时候做什么事情就 能做到的能力。表示现在的能力或一般的能 力时，can比be able to 更普遍。
A computer can’t think for itself; it must be told what to do. （表示一般的能力）
This can’t / couldn’t be done by him. (表示不 相信)
He could be on his way home now. （could 不 如 may / might常用）
Can this be done by him? （表示一种疑惑、 惊讶）
（3）would, could, should, might 并不一定 与过去的时间有关，而是表示可能性弱于他 们相应的现在形式。如：
do something / succeeded in doing sth.
The fire spread through the hotel very
quickly but everyone was able to get out. (过去有能力并成功地做了某事)
(3) could have + 过去分词，表示过去有 能力做但未做。
表示对过去已经发生的行为进行推测，意为 “想必 / 准是/ 一定做了某事
It must have rained last night, for the road was quite muddy.
The lights were out. They must have been asleep.
2. can have done
高中英语高考高考英语语法总复习课件：情态动词课件 (共33张PPT)
done
would r ather
(而做了) 本不必做
(而做了)
宁愿当时没做
her the secr et. You needn ’t have taken a taxi, for it was near to my
house. I would r ather not have
not have done (后悔当时做了) scolded my son.
• 3. 表示习惯性的动作或倾向，“总是，常常”
•
例：When I was a little child, I would go swimming with
•
other children in summer.
• used to do过去常常现在不做了
• would do过去常常有可能现在还在做
• 5. need/dare • 情态动词：没有人称和数的变化，直接接动词原形， • 构成否定和疑问时不用助动词。 • 实意动词：有人称和数的变化，构成否定和疑问时借 • 助助动词do，does，did • 口诀： need，dare真诡异，既有情态又实意。 • 情态动词把to退，实意动词to跟随。 • need doing是特例，=need to be done需牢记。
need to do
• need /want/ requir doing表被动=need /want/ requir to be done
• shall • 1. 征求对方意见或建议，用于第一、第三人称。 • 例：Shall we go now? • 2. 表示允诺、警告、命令，用于第一，二、三人称。 • 例：All of us shall arrive before 5 o’clock. • 3. 表示规章、法令、制度的规定，“必须”=must law,rule做主语时 • 例：The law of Venice says that if anyone tries to kill or • murder any citizen of Venice, everything that he owns shall • be taken away from him.
would r ather
(而做了) 本不必做
(而做了)
宁愿当时没做
her the secr et. You needn ’t have taken a taxi, for it was near to my
house. I would r ather not have
not have done (后悔当时做了) scolded my son.
• 3. 表示习惯性的动作或倾向，“总是，常常”
•
例：When I was a little child, I would go swimming with
•
other children in summer.
• used to do过去常常现在不做了
• would do过去常常有可能现在还在做
• 5. need/dare • 情态动词：没有人称和数的变化，直接接动词原形， • 构成否定和疑问时不用助动词。 • 实意动词：有人称和数的变化，构成否定和疑问时借 • 助助动词do，does，did • 口诀： need，dare真诡异，既有情态又实意。 • 情态动词把to退，实意动词to跟随。 • need doing是特例，=need to be done需牢记。
need to do
• need /want/ requir doing表被动=need /want/ requir to be done
• shall • 1. 征求对方意见或建议，用于第一、第三人称。 • 例：Shall we go now? • 2. 表示允诺、警告、命令，用于第一，二、三人称。 • 例：All of us shall arrive before 5 o’clock. • 3. 表示规章、法令、制度的规定，“必须”=must law,rule做主语时 • 例：The law of Venice says that if anyone tries to kill or • murder any citizen of Venice, everything that he owns shall • be taken away from him.
高中英语语法情态动词完整ppt课件
过去不应该做而实际上做了 （6）needn’t have done 本没有必要做的事实际却做了 （7）could have done
本来能够做的（有能力做）事实际却未做到 （8）must +be doing∕do 表示对现在的动作进行肯定推
测
.
37
• 他现在一定在看小说.
He must be reading novels now. • 他们买了一辆新车。 他们一定很有钱. They have bought a new car. They
.
10
2.Obligation (义务): I’m so tired! I have to do the training for at least 10 hours a day!
Although Liu Xiang is
so gifted in hurdle
race…
…yet he must work
.
26
will/would:
2.表示意志、愿望和决心。 I will never do that again.
.
27
will/would:
3.可表示经常性、习惯性、倾向 性。翻译为“经常、惯于、总是”。
1).The old man
_wo_u_ld____have a
smoke under a
big tree every
.
20
5.Making requests (提出要求): formal
informal
will
can
could
would
I don’t know how to use this
equipment!
Can you help me with my training?
本来能够做的（有能力做）事实际却未做到 （8）must +be doing∕do 表示对现在的动作进行肯定推
测
.
37
• 他现在一定在看小说.
He must be reading novels now. • 他们买了一辆新车。 他们一定很有钱. They have bought a new car. They
.
10
2.Obligation (义务): I’m so tired! I have to do the training for at least 10 hours a day!
Although Liu Xiang is
so gifted in hurdle
race…
…yet he must work
.
26
will/would:
2.表示意志、愿望和决心。 I will never do that again.
.
27
will/would:
3.可表示经常性、习惯性、倾向 性。翻译为“经常、惯于、总是”。
1).The old man
_wo_u_ld____have a
smoke under a
big tree every
.
20
5.Making requests (提出要求): formal
informal
will
can
could
would
I don’t know how to use this
equipment!
Can you help me with my training?
高中英语语法情态动词(28张PPT)-经典通用课件资料
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4. Tom ought not to ___ me your secret,
but he meant no harm.
A. have told
B. tell
C. be telling
D. having told
答案A 由于后句为过去时，告诉秘密的动作又发生在其前因，此地应用过去完成时，但它在情态动词 ought to 后，所以用have。
Must I go there in person? 我必须亲自去吗？ We must always follow the Party.我们要永远跟着党走。 ②表示“必然”
All men must die.人总是要死的。 ③表示推测，“准是”、“一定”，否定形式为can’t
She must be at home now.她现在准在家。
－ May I come in? －Might I go to the hospital to see my father? ②否定形式为may not, 但表示“不可以”或“禁止”时用must not (mustn’t). e.g.－Ｍay I watch TV now?我现在可以看电视吗？ －Ｎo, you mustn’t. 不，你不可以看。 ③ may, might还可以表示推测,但might可能性比may 小。 e.g. There may be a few copies left in the bookstore. 书店里可能还有几本书。 They might have been killed by radiation. ④may 放在句首, 表示祝愿。 e.g. May God bless you!
e.g. You don’t have to tell him about it. 你没必要把此事告诉他。
高中英语语法 情态动词用法总结(20张PPT)-经典通用课件资料
A. could B. would C. should D. might
C
2. What do you mean, there are only ten tickets? There_____
A. should CA. will
B. would D. shall
be twelve.
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5. must
1. 表示义务或强烈的劝告，意为“必须”“应该”， 其否定式表示“不应该”“不许可” “不准”“禁止”。
Eg: 1) You must finish your homework first. 2) Children mustn’t speak like that to their parents.
3. 表推测，用于肯定句，意为“一定”“务必”。
Eg: 1) Betty must be in the next room. 2) He must be watering the flowers in his garden.
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Complete the following sentences using modal verbs.
5) Can/Could I use your dictionary? 6) Could you lend me a hand?
3. 表示“请求” “允许”(表请求时，口语中常用 could 代替 can 使语气更委婉，回答时用can)
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4. 表示“许可”，可与may 换用。 You can go home now.
1. 表“请求、建议”等，用 would 比用will 委婉，客气些 Eg: 1)Will you lend me your book? 2) Would you like a cup of tea?
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It can’t be Mary. She has fallen ill. 她不可能在说谎。
She couldn’t be telling lies.
在疑问句中 could 比can 更有礼貌，在此 不是can的过去式。 e.g. Can you wait a moment please?
Liz, can you do me a favor? Excuse me, could you tell me the way to the station? I wonder if you could help me. (请 求)
对现在或将来情况推测：must +动词原形。 must只能用于肯定。否定和疑问分别用can’t 和can。 e.g. He must tell a lie.
Can he tell a lie ? He can’t tell a lie. *must-should/ought to –may-might/could+do 可能性依次减弱
can could may might shall should must will would 情态动词 ought to have to dare (daren’t) need (needn’t) used to
表示推测 不表示推测
情态动词有一定的意义，但没有人称和数的变化， 不能独立使用，它和后面的动词构成谓语．
3. can/could have done “本可以，本来可能 已经”用于肯定句中，表示对过去发生的事 情做出的判断.
e.g.你本来可以考的更好。 You could have had a better mark.
may/might1.ma来自/might表示推测时，只能用于陈述句， 表示对现在或将来要发生的动作把握不大。 e.g.她们明天可能会到这里来。
(对过去情况推测：must may, might)+完 成时。
e.g. You must have met him before.
must—may—might可能性依次减弱
must只能用于肯定句，译成“一定”。否定 和疑问分别用can’t / couldn’t和can / could。
e.g. Could /Can it have happened last night ?
2.must +be doing/do 表示对现在的动作进行 肯定推测 e.g.他现在一定在看小说.
He must be reading novels now. 他们买了一辆新车。 他们一定很有钱.
They have bought a new car. They must have a lot of money.
只作情态动词的 can/could, may/might, ought to， must
可情态可实义的 need, dare/dared 可情态可助动词的 shall/should, will/would 相当于情态动词的 have to, used to
must , can/could, may/might 的用法
must
1.must 表示推测时， 只能用于肯定句。 e.g.这个电脑肯定出了问题。 There must be something wrong with the computer.
你努力学了一整天， 一定累了吧 You have worked hard all day. You must be tired.
It couldn’t/can’t have happened last night.
can/could
1. can /could 表示推测时，只能用在否定句 或疑问句中。
e.g. It’s so late. Can Tom be reading? Can it be Mr. Green? 这个人不可能是玛丽， 她生病了。
They may come here tomorrow. 他们可能还在等我们呢。
They may be still waiting for us.
2.might 可用于指过去的行为或者表示可能性 更小。 e.g.他也许在做功课吧。 He might be doing his homework now.
3.must +have done 表示对过去发生的事情作 出的肯定判断 e.g.他们在玩篮球， 他们一定完成了作业。
They are playing basketball, they must have finished their homework.
路是湿的。昨天晚上一定下雨了。
The road is wet. It must have rained last night.
He might have read about the news in the newspaper.
我问他我是否可以离开。
I asked him “May I leave now?”
I asked him if I might leave.
3.might/may have done,表示对过去发生的动 作进行可能性推测。
e.g.他可能去医务室了。
He may have gone to the clinic. 他可能已经从报纸上知道这个消息了。
2. can/could have done 对过去发生行为的可 能性进行推测:
刚才我还看见他了， 所以他不可能出国的。 I saw him just now so he couldn’t have gone abroad.
门是锁着的， 所以她不可能在家。 The door was locked. She couldn’t have been at home.
must , can/could, may/might 的用法
注意：must用于肯定句中可表示“偏偏”。 Naturally, after I told her what to do, my daughter must go and do the opposite.
自然地，在我交代女儿做什么之后，她偏偏要 做相反的事情.
She couldn’t be telling lies.
在疑问句中 could 比can 更有礼貌，在此 不是can的过去式。 e.g. Can you wait a moment please?
Liz, can you do me a favor? Excuse me, could you tell me the way to the station? I wonder if you could help me. (请 求)
对现在或将来情况推测：must +动词原形。 must只能用于肯定。否定和疑问分别用can’t 和can。 e.g. He must tell a lie.
Can he tell a lie ? He can’t tell a lie. *must-should/ought to –may-might/could+do 可能性依次减弱
can could may might shall should must will would 情态动词 ought to have to dare (daren’t) need (needn’t) used to
表示推测 不表示推测
情态动词有一定的意义，但没有人称和数的变化， 不能独立使用，它和后面的动词构成谓语．
3. can/could have done “本可以，本来可能 已经”用于肯定句中，表示对过去发生的事 情做出的判断.
e.g.你本来可以考的更好。 You could have had a better mark.
may/might1.ma来自/might表示推测时，只能用于陈述句， 表示对现在或将来要发生的动作把握不大。 e.g.她们明天可能会到这里来。
(对过去情况推测：must may, might)+完 成时。
e.g. You must have met him before.
must—may—might可能性依次减弱
must只能用于肯定句，译成“一定”。否定 和疑问分别用can’t / couldn’t和can / could。
e.g. Could /Can it have happened last night ?
2.must +be doing/do 表示对现在的动作进行 肯定推测 e.g.他现在一定在看小说.
He must be reading novels now. 他们买了一辆新车。 他们一定很有钱.
They have bought a new car. They must have a lot of money.
只作情态动词的 can/could, may/might, ought to， must
可情态可实义的 need, dare/dared 可情态可助动词的 shall/should, will/would 相当于情态动词的 have to, used to
must , can/could, may/might 的用法
must
1.must 表示推测时， 只能用于肯定句。 e.g.这个电脑肯定出了问题。 There must be something wrong with the computer.
你努力学了一整天， 一定累了吧 You have worked hard all day. You must be tired.
It couldn’t/can’t have happened last night.
can/could
1. can /could 表示推测时，只能用在否定句 或疑问句中。
e.g. It’s so late. Can Tom be reading? Can it be Mr. Green? 这个人不可能是玛丽， 她生病了。
They may come here tomorrow. 他们可能还在等我们呢。
They may be still waiting for us.
2.might 可用于指过去的行为或者表示可能性 更小。 e.g.他也许在做功课吧。 He might be doing his homework now.
3.must +have done 表示对过去发生的事情作 出的肯定判断 e.g.他们在玩篮球， 他们一定完成了作业。
They are playing basketball, they must have finished their homework.
路是湿的。昨天晚上一定下雨了。
The road is wet. It must have rained last night.
He might have read about the news in the newspaper.
我问他我是否可以离开。
I asked him “May I leave now?”
I asked him if I might leave.
3.might/may have done,表示对过去发生的动 作进行可能性推测。
e.g.他可能去医务室了。
He may have gone to the clinic. 他可能已经从报纸上知道这个消息了。
2. can/could have done 对过去发生行为的可 能性进行推测:
刚才我还看见他了， 所以他不可能出国的。 I saw him just now so he couldn’t have gone abroad.
门是锁着的， 所以她不可能在家。 The door was locked. She couldn’t have been at home.
must , can/could, may/might 的用法
注意：must用于肯定句中可表示“偏偏”。 Naturally, after I told her what to do, my daughter must go and do the opposite.
自然地，在我交代女儿做什么之后，她偏偏要 做相反的事情.