2004-6-30 11:16
情态动词
情态动词在词义、形态、语法功能方面不同于实义动词、系动词和助动词。
英语的情态动词有: can(could),may(might),must,ought to
此外还有:will(would),shall(should)(也可做助动词), 以及dare,need(也可做实义动词)。
情态动词用性繁多:
1.表示能力、可能、可以:can(could), may(might):
2.表示必须、应该: must,should, ought to;
3.用于询问,请求允许:may(might),can(could),shall(should)
4.表示请求,邀请:will(would),can(could)
5.表示推测与猜想 :can(could),may(might),must;
6..用于目的状语从句中:may(might),can(could),should;
7.用于虚拟语气中:could,would,should,might。
重点难点分析
表示能力,可能,可以:can(could),may(might)
1.The party starts at 8:00. Can you turn up at 7:45? 聚会8:00开始,你能在7:45来吗?
本句还可改写为: Is it possible for you to turn up at 7:45?
2.We can't finish the work in such a short time. 我们不可能在这么短的时间完成这项工作.
本句还可改写为: It's impossible for us to finish the work in such a short time.
3.He has studied English for only three years .But now he can speak it quite well.
他英语只学三年,但现在能讲得很漂亮了.
本句可改写为: Now he is able to speak it quite well.
4.She was a good swimmer, so she was able to swim to the river bank when the boat sank.
她水性好,所以当船沉没时,她游到了河岸. 不能用could,在此只能用was able to 来表示过去的设法完成的动作,
也可以改写为:…so she managed to swim to the river bank.
…so she succeeded in swimming to the river bank.
不管用那种方式表法,字里行间都要有经过努力拼搏,动作才得以完成的意味.
表示必须.应该:must, should, ought to
1.We must get there before dark. 。 我们必须在天黑之前到达那里.
本句可以改写为: It is necessary for us to get there before dark.
或: It's necessary that we (should) get there before dark.
2.You should help each other. 你们应该互相帮助.
本句也可改写为: You ought to help each other.但语气 比前者强烈.
3.---Must I return the book very soon? 一这书我很快就得还吗?
----No you needn't. You can keepit as long as you wish. 一不你想用多久就用多久.
must 在这里的否定形式是: needn't(l不必要).而mustn't表示"禁止","不许"如:
You mustn't cross the road when the lights are red. 红灯时,不许 横穿马路.
用于询问及请求允许:may(might),can(could),shall(should)
l一Can I help you, sir? 一我能为您效劳吗?
-Yes,I bought this radio yesterday, but it doesn't work. 一对,昨天我买了这台收音机,但不好使。
第一句还可改写为: Is there anything I can do for you?
还可缩减成: Anything I can do for you?
can也可用may代替,如:
2.How long may I keep the book? 这书我司以借用多久?
3----Could I use your phone? 一我能借用一下电话吗?
-Yes ,of course, you can. 一请,当然习以。
could用于询问,语气更显得礼貌,但在回答时则不能用,仍须用can。
表示请求邀请:will(would),can(could):
1.Can you explain the sentence to us in simpler English? 请您用简单英语把这个句子给我们讲一下。
can you 也可改为 will you 但更有礼貌的说法是: could you 或would you 要牢记:自己做事情想得到对方的允许要用:May I……要请求对方做事则要用Could(Would) you.....一这应该是脱口而出的。
2.Would you please leave your telephone number with us? 请把您的电话号码给我们留下好吗?
表示推测与猜想:can(could),may(might),must;
l一Can the girl over there be our English teacher? 一那边的那个女孩可能是我们的英语老师吧?
-----She may be,but I'm not sure . 一可能(也许是)但我说不准。
can be ,may be表示对现在事物的判断与推测。
2---Who can it be that turned off the light? 一是谁把灯关了?
-It must be Wang Dong. —一定是王东。
may be为也许(可能)是而must be 则十分肯定, 译为:肯定是(一定是)前者是I'm not sure.。或者:I don't know for sure.而后者则是I'm certain.
用于目的状语从句中:may(might),can(could),should:
1.They asked the driver to stop the beast so that they could have a "look".
他们(指六个盲人)请求赶大象的人停下来让他们“看看”大象是 什么样的
so that (that) , in order that, lest, in case引导目的状语从句从句中要有情态动词may(might),can(could),should.
2.She always takes careful notes in class so that she may review them from time to time.
她总是认真记课堂笔记,为的是好经常复习。
3.They turned the radio up so that everyone might(could) hear the news.
他们把收音机信号开大,以便每个人都能听到新闻。
用于虚拟语气中:could ,would, should,might,
1.If we had more rain, our crops would grow better. 如果雨水多些,庄稼会长的更好些。
从句用一般过去时,主句用情态动词+ 动词 原形,这种虚拟语气的结构用来表示同现存状况相反的事买。
2.If she had taken the doctor's advice, she would have got well already.
如果当初她听大夫的劝告,她的病早好了。
从句用过去完成时,主句用情态动词+ 完成式构 成与过去事买相反的虚拟语气。
3.If a car travelling at 60 miles an hour should go from the earth to the sun ,it would take over 179 years to reach it.
如果有一辆汽车,以每小时60英里的速度,从地球驶向太阳,则需I79多年的时间才能到达那里。
IF ....should do ....would take.....一构成虚拟语气,用来表示将来不太可能买现的事实。
4.We should have studied last night,but we went to the concert instead
昨晚我们本应该学习,但却去听了音乐会。
"should+ 完成式"用来表示过去应该做而没有做的事。
要注意的问题
情态动词中的难点,而且又是近来高考的热点。
一、要注意一些同义、近义的情态动词的区别
1 . 表示可能性的 can’t 与 may not 的区别。
can‘t 常常表示“不可能”、“一定不”,may not 表示“可能不、或许不”。很明显,can’t 比 may not 语气强,把握性大。如:
The man standing over there _____ be Jack . He‘s gone to Hong Kong .
A . mustn’t B . can‘t C . won’t D . may not
说话者既然知道“He‘s gone to Hong Kong”,那么对“The man 不是 Jack”一定满有把握,故正确选项为 B。
2 . 表示“能够”意义的 can 与 be able to 的区别。
凡表示“经过努力、设法做成某事”时不用 can,须用 be able to。如:
The fire spread through the hotel very quickly , but everyone _____ get out . ( NMET97 )
A . had to B . would C . could D . was able to
句意为:大火弥漫整个旅馆,但人位学是设法逃了出来。故正确选项为D。
3 . 表示“不能”意义的 can’t 与 mustn‘t 的区别。
can’t 表示“不能”,是指无能力;mustn‘t 表示“不能”则指的是“禁止,不允许”。在口语里,can’t 也可表示“禁止,不允许”,但语气不如 mustn‘t 强。如:
( 1 ) 他年纪小,不能上学。
He is so young that he can’t go to school .
( 2 ) 里边正在开会,不能吵闹。
There‘s meeting inside . You mustn’t make any noise .
二、要注意几个使用的特定范围
1 . 表示推测时,can 不能用在肯定句中 ( 但 could 能 ) ;may 和 might 不能用在疑问句中。如:
( 1 ) Peter _____ come with us tonight , but he isn’t very sure yet . ( MET93 )
A . must B . may C . can D . will
句意为:Peter 有可能同我们一块儿来,但还不肯定。正确选项为 B。
( 2 ) _____ it be a sunny day tomorrow?
A . Can B . May C . Shall D . Should
句意为:明天可能是睛天吗?正确选项是 A。
2 . 作为情态动词,need 和 dare 不能用在肯定句中 ( 条件状语从句除外 ) 。肯定句中,须把它们用作实义动词,后接带 to 的不定式。如:
误We need hold a meeting to discuss the matter .
正We need to hold a meeting to discuss the matter .
正If you need hold a meeting to discuss the matter , I‘ll give you a help .
3 . 在回答由 could 和 might 引起的表示请示的一般疑问句时,不能用 could 和 might ( 应分别用 can 和 may ) 回答。如:
— Could I borrow your dictionary?
— Yes , of course you _____ . ( MET92 )
A . might B . will C . can D . could
正确选项为 C。
三、要注意一些“形意不一致”的现象
1 . 过去式 could 或 might 后接动词原形可以表示对现在或将来 ( 不是对过去 ) 的推测。如:
I’m afraid it _____ snow tonight .
A . can B . should C . might D . must
2 . may ( not ) 和 can‘t 后接动词的完成式,表示对过去 ( 不是对现在或将来 ) 的推测。如:
— There were already five people in the car but they managed to take me as well .
— It _____ a comfortable journey .
A . can’t have been B . couldn‘t be C . mustn’t have been D . shouldn‘t be
四、要注意情态动词的常用形式的反常使用。
1 . should 和 ought to 后接动词原形,常表示“应该……”;但也可用来表示推测,意为“想必会……”。如:
( 1 ) It’s nearly seven o‘clock . Jack _____ be here ar any moment . ( NMET95 )
A . must B . need C . should D . can
句意为:“快七点钟了,想必杰克随时会到的”。正确选项为 C。
( 2 ) — When can I come for the photos? I need them tomorrow afternoon .
— They _____ be ready by 12∶00 . ( NMET98 )
A . can B . should C . might D . need
句意为“ — 我什么时候来取像片呢?我可是明天下午需要这些像片。”“ — 像片想必会在 ( 明日中午 ) 十二点以前洗出的。”正确选项为 B。情态动词表示推测,语气由强到弱的是:must ( 一定会 ) →ought to / should ( 想必会 ) →can / could ( 可能 ) →may / might ( 也许,或许 ) 。
2 . could 后接完成式常表示“ ( 过去 ) 可能……”,但也可用来表示责备语气,意为 “过去 ) 本来能够……, 而实际上却未…… ”。如:
— We could have walked to the station ; it was so near .
— Yes . A taxi _____ at all necessary . ( NMET92 )
A . wasn’t B . hadn‘t been C . wouldn’t be D . won‘t be
该题虽是一道考查动词时态的考题,但从“We could have walked to the station”可知,实际不是步行去火车站的。结合下句可知是坐了出租车去的,时间是过去,故正确答案是 A。
练习
1.Jenny____have kept her word.I wonder why she changed her mind.(MET1992)?
A.must B.should C.need D.would
2.The monitor must be in the reading-room, ____ he﹖
A.mustn’t B.doesn’t C.needn’t D.isn’t
3.Dr Baker must have given a good speech at the conference yesterday, ____ he﹖
A.mustn’t B.didn’t C.needn’t D.isn’t
4.I told Sally how to get here, but perhaps I ____ for her.?(NMET1994)?
A.had to write it out B.must have written it out
C.should have written it out D.ought to write it out
5.He hardly ____ say anything more, since you know all about it.
A.don’t B.needn’t C.needs D.need?
Key: BDBCD
情态动词在词义、形态、语法功能方面不同于实义动词、系动词和助动词。
英语的情态动词有: can(could),may(might),must,ought to
此外还有:will(would),shall(should)(也可做助动词), 以及dare,need(也可做实义动词)。
情态动词用性繁多:
1.表示能力、可能、可以:can(could), may(might):
2.表示必须、应该: must,should, ought to;
3.用于询问,请求允许:may(might),can(could),shall(should)
4.表示请求,邀请:will(would),can(could)
5.表示推测与猜想 :can(could),may(might),must;
6..用于目的状语从句中:may(might),can(could),should;
7.用于虚拟语气中:could,would,should,might。
重点难点分析
表示能力,可能,可以:can(could),may(might)
1.The party starts at 8:00. Can you turn up at 7:45? 聚会8:00开始,你能在7:45来吗?
本句还可改写为: Is it possible for you to turn up at 7:45?
2.We can't finish the work in such a short time. 我们不可能在这么短的时间完成这项工作.
本句还可改写为: It's impossible for us to finish the work in such a short time.
3.He has studied English for only three years .But now he can speak it quite well.
他英语只学三年,但现在能讲得很漂亮了.
本句可改写为: Now he is able to speak it quite well.
4.She was a good swimmer, so she was able to swim to the river bank when the boat sank.
她水性好,所以当船沉没时,她游到了河岸. 不能用could,在此只能用was able to 来表示过去的设法完成的动作,
也可以改写为:…so she managed to swim to the river bank.
…so she succeeded in swimming to the river bank.
不管用那种方式表法,字里行间都要有经过努力拼搏,动作才得以完成的意味.
表示必须.应该:must, should, ought to
1.We must get there before dark. 。 我们必须在天黑之前到达那里.
本句可以改写为: It is necessary for us to get there before dark.
或: It's necessary that we (should) get there before dark.
2.You should help each other. 你们应该互相帮助.
本句也可改写为: You ought to help each other.但语气 比前者强烈.
3.---Must I return the book very soon? 一这书我很快就得还吗?
----No you needn't. You can keepit as long as you wish. 一不你想用多久就用多久.
must 在这里的否定形式是: needn't(l不必要).而mustn't表示"禁止","不许"如:
You mustn't cross the road when the lights are red. 红灯时,不许 横穿马路.
用于询问及请求允许:may(might),can(could),shall(should)
l一Can I help you, sir? 一我能为您效劳吗?
-Yes,I bought this radio yesterday, but it doesn't work. 一对,昨天我买了这台收音机,但不好使。
第一句还可改写为: Is there anything I can do for you?
还可缩减成: Anything I can do for you?
can也可用may代替,如:
2.How long may I keep the book? 这书我司以借用多久?
3----Could I use your phone? 一我能借用一下电话吗?
-Yes ,of course, you can. 一请,当然习以。
could用于询问,语气更显得礼貌,但在回答时则不能用,仍须用can。
表示请求邀请:will(would),can(could):
1.Can you explain the sentence to us in simpler English? 请您用简单英语把这个句子给我们讲一下。
can you 也可改为 will you 但更有礼貌的说法是: could you 或would you 要牢记:自己做事情想得到对方的允许要用:May I……要请求对方做事则要用Could(Would) you.....一这应该是脱口而出的。
2.Would you please leave your telephone number with us? 请把您的电话号码给我们留下好吗?
表示推测与猜想:can(could),may(might),must;
l一Can the girl over there be our English teacher? 一那边的那个女孩可能是我们的英语老师吧?
-----She may be,but I'm not sure . 一可能(也许是)但我说不准。
can be ,may be表示对现在事物的判断与推测。
2---Who can it be that turned off the light? 一是谁把灯关了?
-It must be Wang Dong. —一定是王东。
may be为也许(可能)是而must be 则十分肯定, 译为:肯定是(一定是)前者是I'm not sure.。或者:I don't know for sure.而后者则是I'm certain.
用于目的状语从句中:may(might),can(could),should:
1.They asked the driver to stop the beast so that they could have a "look".
他们(指六个盲人)请求赶大象的人停下来让他们“看看”大象是 什么样的
so that (that) , in order that, lest, in case引导目的状语从句从句中要有情态动词may(might),can(could),should.
2.She always takes careful notes in class so that she may review them from time to time.
她总是认真记课堂笔记,为的是好经常复习。
3.They turned the radio up so that everyone might(could) hear the news.
他们把收音机信号开大,以便每个人都能听到新闻。
用于虚拟语气中:could ,would, should,might,
1.If we had more rain, our crops would grow better. 如果雨水多些,庄稼会长的更好些。
从句用一般过去时,主句用情态动词+ 动词 原形,这种虚拟语气的结构用来表示同现存状况相反的事买。
2.If she had taken the doctor's advice, she would have got well already.
如果当初她听大夫的劝告,她的病早好了。
从句用过去完成时,主句用情态动词+ 完成式构 成与过去事买相反的虚拟语气。
3.If a car travelling at 60 miles an hour should go from the earth to the sun ,it would take over 179 years to reach it.
如果有一辆汽车,以每小时60英里的速度,从地球驶向太阳,则需I79多年的时间才能到达那里。
IF ....should do ....would take.....一构成虚拟语气,用来表示将来不太可能买现的事实。
4.We should have studied last night,but we went to the concert instead
昨晚我们本应该学习,但却去听了音乐会。
"should+ 完成式"用来表示过去应该做而没有做的事。
要注意的问题
情态动词中的难点,而且又是近来高考的热点。
一、要注意一些同义、近义的情态动词的区别
1 . 表示可能性的 can’t 与 may not 的区别。
can‘t 常常表示“不可能”、“一定不”,may not 表示“可能不、或许不”。很明显,can’t 比 may not 语气强,把握性大。如:
The man standing over there _____ be Jack . He‘s gone to Hong Kong .
A . mustn’t B . can‘t C . won’t D . may not
说话者既然知道“He‘s gone to Hong Kong”,那么对“The man 不是 Jack”一定满有把握,故正确选项为 B。
2 . 表示“能够”意义的 can 与 be able to 的区别。
凡表示“经过努力、设法做成某事”时不用 can,须用 be able to。如:
The fire spread through the hotel very quickly , but everyone _____ get out . ( NMET97 )
A . had to B . would C . could D . was able to
句意为:大火弥漫整个旅馆,但人位学是设法逃了出来。故正确选项为D。
3 . 表示“不能”意义的 can’t 与 mustn‘t 的区别。
can’t 表示“不能”,是指无能力;mustn‘t 表示“不能”则指的是“禁止,不允许”。在口语里,can’t 也可表示“禁止,不允许”,但语气不如 mustn‘t 强。如:
( 1 ) 他年纪小,不能上学。
He is so young that he can’t go to school .
( 2 ) 里边正在开会,不能吵闹。
There‘s meeting inside . You mustn’t make any noise .
二、要注意几个使用的特定范围
1 . 表示推测时,can 不能用在肯定句中 ( 但 could 能 ) ;may 和 might 不能用在疑问句中。如:
( 1 ) Peter _____ come with us tonight , but he isn’t very sure yet . ( MET93 )
A . must B . may C . can D . will
句意为:Peter 有可能同我们一块儿来,但还不肯定。正确选项为 B。
( 2 ) _____ it be a sunny day tomorrow?
A . Can B . May C . Shall D . Should
句意为:明天可能是睛天吗?正确选项是 A。
2 . 作为情态动词,need 和 dare 不能用在肯定句中 ( 条件状语从句除外 ) 。肯定句中,须把它们用作实义动词,后接带 to 的不定式。如:
误We need hold a meeting to discuss the matter .
正We need to hold a meeting to discuss the matter .
正If you need hold a meeting to discuss the matter , I‘ll give you a help .
3 . 在回答由 could 和 might 引起的表示请示的一般疑问句时,不能用 could 和 might ( 应分别用 can 和 may ) 回答。如:
— Could I borrow your dictionary?
— Yes , of course you _____ . ( MET92 )
A . might B . will C . can D . could
正确选项为 C。
三、要注意一些“形意不一致”的现象
1 . 过去式 could 或 might 后接动词原形可以表示对现在或将来 ( 不是对过去 ) 的推测。如:
I’m afraid it _____ snow tonight .
A . can B . should C . might D . must
2 . may ( not ) 和 can‘t 后接动词的完成式,表示对过去 ( 不是对现在或将来 ) 的推测。如:
— There were already five people in the car but they managed to take me as well .
— It _____ a comfortable journey .
A . can’t have been B . couldn‘t be C . mustn’t have been D . shouldn‘t be
四、要注意情态动词的常用形式的反常使用。
1 . should 和 ought to 后接动词原形,常表示“应该……”;但也可用来表示推测,意为“想必会……”。如:
( 1 ) It’s nearly seven o‘clock . Jack _____ be here ar any moment . ( NMET95 )
A . must B . need C . should D . can
句意为:“快七点钟了,想必杰克随时会到的”。正确选项为 C。
( 2 ) — When can I come for the photos? I need them tomorrow afternoon .
— They _____ be ready by 12∶00 . ( NMET98 )
A . can B . should C . might D . need
句意为“ — 我什么时候来取像片呢?我可是明天下午需要这些像片。”“ — 像片想必会在 ( 明日中午 ) 十二点以前洗出的。”正确选项为 B。情态动词表示推测,语气由强到弱的是:must ( 一定会 ) →ought to / should ( 想必会 ) →can / could ( 可能 ) →may / might ( 也许,或许 ) 。
2 . could 后接完成式常表示“ ( 过去 ) 可能……”,但也可用来表示责备语气,意为 “过去 ) 本来能够……, 而实际上却未…… ”。如:
— We could have walked to the station ; it was so near .
— Yes . A taxi _____ at all necessary . ( NMET92 )
A . wasn’t B . hadn‘t been C . wouldn’t be D . won‘t be
该题虽是一道考查动词时态的考题,但从“We could have walked to the station”可知,实际不是步行去火车站的。结合下句可知是坐了出租车去的,时间是过去,故正确答案是 A。
练习
1.Jenny____have kept her word.I wonder why she changed her mind.(MET1992)?
A.must B.should C.need D.would
2.The monitor must be in the reading-room, ____ he﹖
A.mustn’t B.doesn’t C.needn’t D.isn’t
3.Dr Baker must have given a good speech at the conference yesterday, ____ he﹖
A.mustn’t B.didn’t C.needn’t D.isn’t
4.I told Sally how to get here, but perhaps I ____ for her.?(NMET1994)?
A.had to write it out B.must have written it out
C.should have written it out D.ought to write it out
5.He hardly ____ say anything more, since you know all about it.
A.don’t B.needn’t C.needs D.need?
Key: BDBCD
学会忘记 学会一个人
沉浸在黑暗深渊之中
六对翅膀撑起了太多的失落
沉浸在黑暗深渊之中
六对翅膀撑起了太多的失落

