内容正文:
专题五 情态动词
情态动词表示说话人的情绪、态度或语气,没有人称和数的变化,本身有一定的词义,但是不能单独作谓语,只能和其他动词原形一起构成谓语。情态动词具有助动词的作用,可用来构成否定句、疑问句以及用于简单答语,在句中位于实义动词之前。
初中
考点
·情态动词与基本用法
·情态动词的区别
高中
考点
·情态动词与完成时连用意义及区别
·情态动词在虚拟语气中的用法
一、常见情态动词的用法
情态动词
表示
一般疑问句
肯定或否定回答
can/
could
能力
Can she drive the car?
她会开这辆车吗?
No,she can't.
不,她不会。
may/
might
允许,
可能
May I have aswim here?
我可以在这儿游泳吗?
May I sit here?
我能坐在这儿吗?
No,you mustn't.不,你不准。
No,you can't.不,你不能。
must
必须
Must I come here on time?
我必须准时到这儿吗?
No,you needn't/don't have to.
不,你不必。
should
应该
Should we help her do it?
我们应该帮助她做这件事吗?
No,we shouldn't.
不,我们不应该。
need
需要
Need you go now?
现在你有必要走吗?
Yes,I must.对,我必须走。
No,I needn't.不,我不必走。
其他的情态动词还有ought to(应该),dare(敢于)。如:
We ought to help each other in our work.
在工作中我们应该互相帮助。
Dare you go home alone?你敢一个人回家吗?
二、情态动词的用法比较
1.can和be able to的用法比较
can表示“能力;许可”,只用于一般现在时和一般过去时,而be able to表示“经过努力而能够做某事”,可用于多种时态。如:
He can swim.他会游泳。
He was able to swim across the English Channel last week.
上周他成功地游过了英吉利海峡。
2.must和have to的区别
must侧重于个人意志和主观上的必要;have to侧重于客观上的需要。如:
We must obey the rules.
我们必须遵守规则。
My mother is ill,I have to look after my little sister.
我妈妈病了,我不得不照顾我的妹妹。
3.can与may表示可能性时的区别
(1)肯定句中用may表示可能。如:
You'd better ask the monitor.He may know.你最好问班长,他可能知道。
(2)在否定句中,若语气肯定,表示“不可能”时用can't;若语气不肯定,表示“可能不”时用may not。如:Mr.Li can't be in.He has gone to Beijing for a meeting.
李先生不可能在家,他去北京开会了。
4.need后加to do说明need为实义动词,需借用助动词构成疑问句或否定句;若needn't后加do,则need为情态动词,此时由need引导的一般疑问句,若是肯定回答,不用need,用must。如:
This soup needs salt.这汤需要放盐。
—Need he sweep the floor now?
—Yes,he must.
——他必须现在扫地吗?
——是的,他必须扫。
5.一般来说,could是can的过去式,但在某些场合下,could可以用来代替can,表示现在的情况,只是语气比can委婉,此时,若是用could来提问,回答时用can,而不用could。如:
—Could you answer me a question?
—Yes,I can./No,I can't.
——请你回答我一个问题好吗?
——好。/不行。
6.may be和maybe
(1)may be意为“可能是,也许是”,由情态动词may+动词原形be构成,用在句中,作谓语。如:I can't find my book.It may be in your bag.
我找不到我的书了,它可能在你的包里。
(2)maybe为副词,意为“大概,也许”,作状语,相当于perhaps,用于句首。如:
Maybe you put your letter in your pocket.
也许你把信放在你的口袋里。
(3)maybe和may be可以互换,但要做些改变。如:He may be at home now.=Maybe he is at home now.
他现在可能在家。
一、shall的用法
在初中英语中,shall用于第一人称肯定句中表示将来,疑问句中表示征求对方的许可,或者征求对方的建议。
We shall(=will)go swimming this afternoon.
今天下午我们将去游泳。(将来)
Shall I sit here? 我可以坐在这吗?(许可)
Shall we have a rest? 我们休息一下好吗?
高中英语中,shall的功能有所扩展。
1.用于第一人称表示决心。
We shall overcome any difficulty we will meet in carrying out the plan.
我们要克服一切在实施此计划中所遇到的一切困难。
2.用于一、三人称疑问句中,请求对方许可,表示“你同意与否”。
Shall I turn on the TV?
我打开电视行吗?(你同意吗?)
Shall the man standing out come in?
让外边站着的人进来吗?
Shall my students have a try?
让我的学生试试吧?
3.用于二、三人称肯定句中,表示“威胁,命令,警告”等。
You shall be punished if you continue to do so.你若继续这样,快挨罚了。
He shall come here early tomorrow.
他明天要早到。
4.用于第三人称肯定句中表示“法律条文、规章制度”等规定或要求所做之事。
No one shall smoke in this area.
任何人在此不得吸烟。
二、情态动词+have+过去分词
1.can/could have done表示“本来可以做,而实际上未做”或者“过去可能”,疑问或否定形式表示对过去发生行为表示怀疑或不肯定,其中can't have done多用于语气强烈的否定,意为“不可能做过”。
—Do you know where Tom is? I couldn't find him anywhere.
—Well.He can't have gone far—his coat's still here.
——你知道汤姆在哪儿吗?我到处都找不到他。
——噢,他不可能走远,他的衣服还在这儿。
2.must have done表示对过去行为的推测,意为“一定;想必”,语气十分肯定。
He is very happy.He must have passed the exam.
他非常高兴,他肯定通过了考试。
3.may/might have done可能做过……
should have done本应该做某事而实际未做
need have done本必要做某事而实际未做
Ⅰ.根据语境用适当的情态动词填空
1.—Could I borrow your dictionary?
—Yes,of course you ________.
2.—What are you doing this Saturday?
—I'm not sure,but I ________ go to a concert.
3.—May I go now?
—No,you ________.
4.—Must I finish the project today?
—No,you ________.
5.________you tell me the way to the station?
6.Mary ________be in the classroom.I saw her on the playground just now.You ________have made a mistake.That girl ________be Jenny.
7.— ________ I use your bicycle?
— Certainly,you ________.But it ______be returned before six o'clock this afternoon.
8.—________you go and travel there with me next week?
— I'd like to.But I ________.I have a lot of things to do then.________we go next month?
— Well,see you!
Ⅱ.完成句子
1. 有时候,压力和焦虑会成为创造力的阻碍。
Sometimes stress and anxiety can ________________ of creativity.
2.我在乡下待了一个月之后,觉得不习惯住在大城市了。
After staying in the country for a month, I didn't think I could ________________ in a big city.
3.众所周知,阅读可以对人的一生产生重要的影响。
As we all know, reading can ________________ to the whole life of a person.
4.作为一名高中生,你必须努力提高你的沟通和解决问题的能力。
As a senior high school student, you must ______________ improve your ________ and ______________________________.
5.要想提高你的写作水平,你最好把每天写日记当成习惯。
To improve your writing,________________.
6.当你拜访一位中国朋友的时候,带个礼物是有礼貌的,比如一束花。
________________, such as a bunch of flowers, when you visit a Chinese friend.
7.只有通过均衡饮食,定期锻炼,你才能既保持体形又保持健康。
Only by means of balanced diets and regular exercise ____________________.(倒装句)
8.得知你每天有许多的问题要解决,我建议你开始认真考虑哪个问题是最紧急的。
Learning that ______________________, I suggest that ________________ which one is the most urgent.
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专题五 情态动词
语法要点专练
Ⅰ.
1.can 2.might 3.mustn't 4.needn't 5.Would 6.can't;must;may 7.May;can;must 8.Will;can't; Shall
Ⅱ.
1.get in the way 2.get used to living 3.make an important difference 4.make efforts to communication problemsolving skills 5.you'd better make it a rule to keep a diary every day 6.It's good manners to bring a gift 7.can you keep your figure as well as stay healthy
8.you have so many problems to settle every day you (should) settle down to considering
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