情态动词
情态动词（ model verb） 用来表示能力、
允许、可能、必须、劝告、意愿等概念或态
度。主要的情态动词有 can （ could）,may
（ might）,shall （ should）,will （ would），
must,ought to,need,dare等。情态动词没有
人称和数的变化，其后常跟不带 to的不定式。
1,情态动词的一般用法,
? (1) 表示能力, can,could,be able to
? He is over 80 but still can read without
glasses,
? She couldn't come yesterday,
? He can’t come tomorrow,
?? can/could 与 be able to 用法比较
? 1） be able to 除有一般现在时, 一般过去时, 一般将来
时外, 还可有现在完成时, 不定式, 动词 -ing 形式等 。
? This is the information I’ve been able to get so far,
? To be able to ride a bike,she practiced a lot,
? Just being able to drive a horse,a cart isn’t much help to
us,
? 2) could表示过去总的、经常性的能力； was/were able
to 表示过去具体情况下具有的能力，并且做了某动作。
? He could speak French,so he was able to show the French
lady the way,
? 3) 表示将来的能力常用 will be able to,
? When will you be able to take us to town?
(2) 表示许可,can/could,may/might; can’t,may
not,mustn’t,must not
? 1) 征询, 许可, 或给予, 许可, 可用 can/could 或 may/might 表示 。
May 用于正式场合, can 用于非正式场合, could 用于客气的询问,
might 极少用 。
? You can go at four o’clock,
? Could I borrow your pen?
? Students may take 3 books each,
? Might I ask whether you are using the typewriter?
? 2) 表示, 不允许, 用 can’t,may not,mustn’t； must not 语气重 。
? You can’t leave the table unless you finish your meal,
? Put that cigarette out,You must not smoke near a petrol pump!
? 3) 表示过去, 许可, 不用 could,might,要用其他表达方式 。
? We had been/were given permission to speak to the patient,
? 但在间接引语中表达过去, 许可,, 可用 could,might。
? The nurse said that we could/might speak to the patient for just a few
minutes,
(3) 表示可能性,may/might,can/could,must;
can’t
? 1） may,might 用来推测现在, 可能, ； may比 might表示的可
能性大些 。
? Why isn’t John in class? He may/might be sick,
? maybe是副词, 不是情态动词 。 Maybe he is sick,
? 2) 在日常口语中常用 can/could 表示, 可能, 。
? You can/could walk for miles in the country without meeting
anyone,
? Can the news be true? No,it can’t be true,
? 3) must表示可能性最大,, 必定, ；否定形式用 can’t表示
,肯定不,,, 必定不会, 。
? You must be hungry after a long walk,
? The phone is ringing,but there is no answer,She can’t be at home,
（ 4）表示必须和需要,must,have to,need
? 1） must表示说话人认为, 必须, ；否定回答
时用 needn’t,不必, 。
? You must be here at nine o’clock,
? Must you go soon? No,I needn’t go yet,
? 2) have to 表示他人或客观情况要求, 必须, 。
? I have to be back at school by eight,I have a lot
of work to do tonight,
? We don’t have to wear uniforms in school,
? ? 口语中常用 have got to 表示, 必须, 。
? I have got to leave now,I have a meeting in ten
minutes,
? 3) need 表示动作者, 需要,,, 有必
要,, 用于否定句或疑问句；肯定回答
用 must,否定回答用 needn’t。
? Need he go now? Yes,he must,No he
needn’t,
?? need 常用作实义动词 。
? You need to learn the value of time,
? You didn’t need to tell him the news,
? Does she need to go?
?
（ 5）表示责任和劝告, should,ought to,must,had better
? 1) 用 should和 ought to 表示责任和劝告, 后者的
语气重些
? You should/ought to do as you are told,
? Such things shouldn't/ought not to be allowed,
? 2) 有时也用 must 表示责任和劝告 。
? You must see the movie,It’s wonderful,
? 3) 口语中也常用 had better 表示劝告, 意为, 最
好做 /不做某事, 。
? You had better take care of yourself,
? You’d better not make a mistake next time,
? Hadn’t you better see who is at the door?
（ 6）表示建议,shall,may/might as well,
may/might just as well
? 1), shall I/we…, 表示征求对方对建议的看法 。
? Shall we carry the boxes into the house?
? Let’s go,shall we?
? 2) may/might as well,may/might just as well 表
示推荐更佳方案, 建议另一种做法, 意为, 倒
不如 ……,,, …… 不也一样吗？, 。
? We may as well stay here tonight,
? You might just as well tell the truth,
(7) 表示许诺,shall
? shall用于第二, 三人称, 表示说话
人的许诺 。
? You shall have your money back next
week,
? If he passes the exam,he shall have a
holiday,
(8) 表示意愿,shall,will/would
? 1) you/he/they shall 表示说话人的强烈意愿, 甚
至威胁 。
? You shall pay for this,
? They shall do what I tell them to do,
? ? 在法律条文, 规章制度中, shall 表示, 必
须, 。
? Each competitor shall wear a number,
? 2) will/would 表示动作者愿意 。
? I will lend you the book if you need it,
? I won’t do it again,
? I have been trying to open the door,but the key won’t turn,
? ?,will you/would you…, 在下列句中表示客气的建
议, 询问 。
? Will you please have a drink?
? Would you please pass me the salt?
? Would you like a cup of tea?
? Would you mind if I opened the window?
? Would you mind opening the window? Would you mind
my opening the window?
? ? would 还表示过去的习惯 。 等于 used to
? On Sundays he would get up early and go fishing,
?
(9)表示勇敢,dare
? dare 表示, 敢于,, 用于否定句, 疑问句或条
件句 。
? He dare not try,
? How dare you open the letter?
? If you dare say a word,I’ll strike you down,
? ? dare 还常用作实义动词 。
? He dare to surf in heavy waters,
? ? daresay 或 dare say,表示 probably,I
suppose,
? I dare say he will come home late,
2,情态动词的特殊用法
? （ 1） 情态动词 +不定式完成时
? 1） can/could,may/might,must + have + 动词的过去分词
? 用于肯定句：表示对过去事件的主观判断, 推测过去某动作
,可能,,, 也许,,, 一定, 已发生 。
? Tom could have taken the dictionary,I saw him using it last
Sunday,
? I can’t find my sunglasses,I may/might have left them at the
restaurant yesterday,
? You screamed in your sleep last night,You must have had a
terrible dream,
? 用于否定句：表示推测过去某动作, 可能,,, 也许,,
,一定, 没有发生 。
? She couldn't have finished her work so soon,
? She may not have seen you,
? Dad mustn't have washed the dishes last night,
? 2) should/ought to + have + 动词的过去分词 。
? 用于肯定句：评论过去, 应该做, 而实际并未
做的动作, 意为, 本应该, 。
? I didn't ask her,It’s a pity,You should have asked
her,You ought to have asked everyone,
? 用于否定句：评论过去, 不应该做, 而实际做
了的动作, 意为, 本不应该, 。
? I only told Mike,You shouldn't have told anyone,
You ought not to have told anyone,
? 3) needn’t + have + 动词的过去分词
? 对过去已经发生的动作进行评论, 认为
,无须发生,,, 不必做, 。
? I needn’t have put on my best suit to go to
the party; most of the guests were wearing
jeans,
? We went to the meeting,but it had been
cancelled,Oh,so you needn’t have gone,
(2) 情态动词 + 不定式进行时
? 表示推测或评论某动作现在是否正在进
行 。
? She may be washing her clothes,
? He can’t be working now,
? He must be studying in the library,
? They shouldn't be watching TV now,They
should be doing homework,
(3) 情态动词 + 不定式完成进行时
情态动词 + have been + 动词的现在分词, 表示推
测或评论过去某动作是否正在进行或一直在进行 。
He may have been buying stamps in the post office
when you saw him,
She must have been working then,
She should have been attending a meeting yesterday
morning,
They shouldn't have been chatting while working,
情态动词（ model verb） 用来表示能力、
允许、可能、必须、劝告、意愿等概念或态
度。主要的情态动词有 can （ could）,may
（ might）,shall （ should）,will （ would），
must,ought to,need,dare等。情态动词没有
人称和数的变化，其后常跟不带 to的不定式。
1,情态动词的一般用法,
? (1) 表示能力, can,could,be able to
? He is over 80 but still can read without
glasses,
? She couldn't come yesterday,
? He can’t come tomorrow,
?? can/could 与 be able to 用法比较
? 1） be able to 除有一般现在时, 一般过去时, 一般将来
时外, 还可有现在完成时, 不定式, 动词 -ing 形式等 。
? This is the information I’ve been able to get so far,
? To be able to ride a bike,she practiced a lot,
? Just being able to drive a horse,a cart isn’t much help to
us,
? 2) could表示过去总的、经常性的能力； was/were able
to 表示过去具体情况下具有的能力，并且做了某动作。
? He could speak French,so he was able to show the French
lady the way,
? 3) 表示将来的能力常用 will be able to,
? When will you be able to take us to town?
(2) 表示许可,can/could,may/might; can’t,may
not,mustn’t,must not
? 1) 征询, 许可, 或给予, 许可, 可用 can/could 或 may/might 表示 。
May 用于正式场合, can 用于非正式场合, could 用于客气的询问,
might 极少用 。
? You can go at four o’clock,
? Could I borrow your pen?
? Students may take 3 books each,
? Might I ask whether you are using the typewriter?
? 2) 表示, 不允许, 用 can’t,may not,mustn’t； must not 语气重 。
? You can’t leave the table unless you finish your meal,
? Put that cigarette out,You must not smoke near a petrol pump!
? 3) 表示过去, 许可, 不用 could,might,要用其他表达方式 。
? We had been/were given permission to speak to the patient,
? 但在间接引语中表达过去, 许可,, 可用 could,might。
? The nurse said that we could/might speak to the patient for just a few
minutes,
(3) 表示可能性,may/might,can/could,must;
can’t
? 1） may,might 用来推测现在, 可能, ； may比 might表示的可
能性大些 。
? Why isn’t John in class? He may/might be sick,
? maybe是副词, 不是情态动词 。 Maybe he is sick,
? 2) 在日常口语中常用 can/could 表示, 可能, 。
? You can/could walk for miles in the country without meeting
anyone,
? Can the news be true? No,it can’t be true,
? 3) must表示可能性最大,, 必定, ；否定形式用 can’t表示
,肯定不,,, 必定不会, 。
? You must be hungry after a long walk,
? The phone is ringing,but there is no answer,She can’t be at home,
（ 4）表示必须和需要,must,have to,need
? 1） must表示说话人认为, 必须, ；否定回答
时用 needn’t,不必, 。
? You must be here at nine o’clock,
? Must you go soon? No,I needn’t go yet,
? 2) have to 表示他人或客观情况要求, 必须, 。
? I have to be back at school by eight,I have a lot
of work to do tonight,
? We don’t have to wear uniforms in school,
? ? 口语中常用 have got to 表示, 必须, 。
? I have got to leave now,I have a meeting in ten
minutes,
? 3) need 表示动作者, 需要,,, 有必
要,, 用于否定句或疑问句；肯定回答
用 must,否定回答用 needn’t。
? Need he go now? Yes,he must,No he
needn’t,
?? need 常用作实义动词 。
? You need to learn the value of time,
? You didn’t need to tell him the news,
? Does she need to go?
?
（ 5）表示责任和劝告, should,ought to,must,had better
? 1) 用 should和 ought to 表示责任和劝告, 后者的
语气重些
? You should/ought to do as you are told,
? Such things shouldn't/ought not to be allowed,
? 2) 有时也用 must 表示责任和劝告 。
? You must see the movie,It’s wonderful,
? 3) 口语中也常用 had better 表示劝告, 意为, 最
好做 /不做某事, 。
? You had better take care of yourself,
? You’d better not make a mistake next time,
? Hadn’t you better see who is at the door?
（ 6）表示建议,shall,may/might as well,
may/might just as well
? 1), shall I/we…, 表示征求对方对建议的看法 。
? Shall we carry the boxes into the house?
? Let’s go,shall we?
? 2) may/might as well,may/might just as well 表
示推荐更佳方案, 建议另一种做法, 意为, 倒
不如 ……,,, …… 不也一样吗？, 。
? We may as well stay here tonight,
? You might just as well tell the truth,
(7) 表示许诺,shall
? shall用于第二, 三人称, 表示说话
人的许诺 。
? You shall have your money back next
week,
? If he passes the exam,he shall have a
holiday,
(8) 表示意愿,shall,will/would
? 1) you/he/they shall 表示说话人的强烈意愿, 甚
至威胁 。
? You shall pay for this,
? They shall do what I tell them to do,
? ? 在法律条文, 规章制度中, shall 表示, 必
须, 。
? Each competitor shall wear a number,
? 2) will/would 表示动作者愿意 。
? I will lend you the book if you need it,
? I won’t do it again,
? I have been trying to open the door,but the key won’t turn,
? ?,will you/would you…, 在下列句中表示客气的建
议, 询问 。
? Will you please have a drink?
? Would you please pass me the salt?
? Would you like a cup of tea?
? Would you mind if I opened the window?
? Would you mind opening the window? Would you mind
my opening the window?
? ? would 还表示过去的习惯 。 等于 used to
? On Sundays he would get up early and go fishing,
?
(9)表示勇敢,dare
? dare 表示, 敢于,, 用于否定句, 疑问句或条
件句 。
? He dare not try,
? How dare you open the letter?
? If you dare say a word,I’ll strike you down,
? ? dare 还常用作实义动词 。
? He dare to surf in heavy waters,
? ? daresay 或 dare say,表示 probably,I
suppose,
? I dare say he will come home late,
2,情态动词的特殊用法
? （ 1） 情态动词 +不定式完成时
? 1） can/could,may/might,must + have + 动词的过去分词
? 用于肯定句：表示对过去事件的主观判断, 推测过去某动作
,可能,,, 也许,,, 一定, 已发生 。
? Tom could have taken the dictionary,I saw him using it last
Sunday,
? I can’t find my sunglasses,I may/might have left them at the
restaurant yesterday,
? You screamed in your sleep last night,You must have had a
terrible dream,
? 用于否定句：表示推测过去某动作, 可能,,, 也许,,
,一定, 没有发生 。
? She couldn't have finished her work so soon,
? She may not have seen you,
? Dad mustn't have washed the dishes last night,
? 2) should/ought to + have + 动词的过去分词 。
? 用于肯定句：评论过去, 应该做, 而实际并未
做的动作, 意为, 本应该, 。
? I didn't ask her,It’s a pity,You should have asked
her,You ought to have asked everyone,
? 用于否定句：评论过去, 不应该做, 而实际做
了的动作, 意为, 本不应该, 。
? I only told Mike,You shouldn't have told anyone,
You ought not to have told anyone,
? 3) needn’t + have + 动词的过去分词
? 对过去已经发生的动作进行评论, 认为
,无须发生,,, 不必做, 。
? I needn’t have put on my best suit to go to
the party; most of the guests were wearing
jeans,
? We went to the meeting,but it had been
cancelled,Oh,so you needn’t have gone,
(2) 情态动词 + 不定式进行时
? 表示推测或评论某动作现在是否正在进
行 。
? She may be washing her clothes,
? He can’t be working now,
? He must be studying in the library,
? They shouldn't be watching TV now,They
should be doing homework,
(3) 情态动词 + 不定式完成进行时
情态动词 + have been + 动词的现在分词, 表示推
测或评论过去某动作是否正在进行或一直在进行 。
He may have been buying stamps in the post office
when you saw him,
She must have been working then,
She should have been attending a meeting yesterday
morning,
They shouldn't have been chatting while working,
