英语助动词和情态动词及练习一、概述不同的时态(一般式、进形式、完成式、将来式),不同的语态(主动、被动),不同的语气(祈使、陈述、虚拟),不同的结构(肯定、否定、疑问),以及说话者本身的态度或命令、请求、愿望、可能等,所有这些都要借助于助动词和情态动词表达出来。
助动词一般没有词意,不能单独作谓语动词,除非省略句中。
他们只参加时态、语态、语气或否定、疑问结构。
情态动词有词义,可以用来表示说话者的语气和态度。
主要的助动词和情态动词如下表:二、助动词助动词一般没有词意,不能单独作谓语动词。
其作用在于帮助构成各种时态、语态、否定、疑问等。
1、助动词be(am, is, are, was, were, being, been)的用法(1) be后跟现在分词构成进行时态。
Who is playing the violin?谁在拉小提琴?She was reading a book then.那时她正在读书。
(2)be后跟过去分词构成被动语态。
He was asked to do the work.有人要他干这件工作。
You are invited to attend the meetintg.有人邀请你参加会议。
(3)be 后跟不定式作谓语,有如下几种情况:①表示计划、安排将要发生的事。
Who are we to meet?我们要见谁呀?I'm to have supper with John this afternoon.今天下午我要与约翰一起吃晚饭。
②表示指示、命令,否定式表禁止。
You are to see the headmaster today.今天你必须去见校长。
You are not to enter the room without permission.未经允许你不能进入房间。
③表示义务、责任等,同should。
You are to be back before 5.你得在5点钟以前回来。
What is to be done?该干什么。
④表示可能性,与情态动词may, can同义。
Such books are to be found in any library.这种书任何图书馆都有。
Not a sound was to be heard.一点声响也没有。
⑤表示后来发生的事,可以用来表示命运或注定They say good-bye, little knowing that they were never to meet again.他们告别了,没想到再也不能相见了。
He was to regret the decision.他有一天会后悔做出这一决定的。
⑥用于习语Where am I to go? 我该向何处去?What am I to do? 我该怎么办?2、助动词have(has, had, having)的用法(1)助动词have可以构成完成时或完成进行时He has been a doctor for 10 years.他当医生十年了。
This is the place I have been longing to visit.这就是我一直渴望参观的地方。
(2)和不定式构成谓语,表示客观上不得不做的事情。
We've missed the train. We'll have to wait for another one.我们己经误了火车,我们只能等下一列。
-Do we have to start work?我们得立刻工作吗?-No. We don't have to.不,不必了。
3、do(does, did) 的用法(1)构成疑问句或否定句How did you know about it?你是怎样知道这件事的。
He does not smoke. 他不抽烟。
(2)加强语气。
He did tell that.他的确告诉了此事。
Do come and see us.一定来看我们。
(3)代替前面刚出现的动词,避免重复。
-You like popular music, don't you?你喜欢流行音乐,是吧?-Yes , I do.是的,我喜欢。
He speaks French as fluently as she does.他讲法语和她讲的一样流利。
(4)用于倒装句中。
Never did he pay attention to my words.他从不注意我的话。
Only then did I understand the importance of English.只是那时,我才了解到英语的重要性。
(5)构成否定的祈使句。
Don't be so careless.不要那么粗心。
Do not hesitate to come for help.只管来求助。
4、shall(should)和will(would) 的用法(1)shall(should)用于第一人称的将来时中,单纯表示来I shall think it over.我要好好考虑一下。
When shall I see you again?我何时再见到你?I rang up to tell her that I should leave for London. 我打电话告诉她我要去伦敦。
(2)will用于第二、第三人称的将来时态中,在现代英语中可以用于所有人称He will be 30 next month. 他下月将是30岁。
You will have an English test tomorrow.明天你有英语小测验。
He wanted to know when you would finish the writing.他想知道你何时完成写作。
三、情态动词1、情态动词的特征情态动词表示说话人对某一动作或状态的态度,认为“可能、应当、必要”等等,但本身意义不完全,不能单独作谓语,必须和其他动词一起构成谓语。
除ought, used, have后跟不定式外,其他情态动词一律跟动词原形。
情态动词主要有:can/could, may/might, must, ought to, used to, need, dare, shall/should, will/would, have to等。
2、情态动词的变化形式(1)没有人称和数的变化。
I can /we can/ you can he can/she can/they can/it canJohnny, you mustn’t play with the knife, you may hurt yourself.约翰,你不能玩刀,那可能会伤着你。
A left luggage office is a place where bags can be left for a short time, especially at a railway station.行李寄存处特别是在火车站短时间存放包的地方。
He ought to know her address.他该知道她的地址。
(2)大部分情态动词有过去式:can-could may-might need-needed dare-dared shall-should will-would– Is John coming by train?约翰坐火车来吗?– He should, but he may not. He likes driving his car.应该是,他有可能不乘坐火车。
他喜欢开车。
- Are you coming to Jeff's party?你来参加Jeff的聚会吗?- I'm not sure. I might go to the concert instead. 我不敢肯定,我可能去参加音乐会。
(3)少部分情态动词没过去式或者说过去式与原形相同,used to 只有过去式形式。
must-must(had to) ought to -ought toI used to go there.我(以前)常到那里去。
You must be tired after your long journey. 你走了这么远的路,一定很累。
(4)大多数情态动词后面还可跟动词的进行时、完成时和被动式形式:can/may/must+ be doing/have done/be doneshould/would/might+be doing/have done/be doneHe must have earned a large sum of money.他一定是挣了一笔巨款。
You mustn’t always be talking so much.你不能总是说起来没完没了。
3、否定式和疑问式情态动词的否定式和疑问式同助动词。
否定式是在情态动词后加not;疑问式是将情态动词提前到主语的前面。
-Will you stay for lunch? 你留下来吃午饭好吗?-Sorry, I can’t. My brother is coming to see me. 对不起,我不能(留下来吃午饭),我兄弟要来看我。
May I ask you a question?我可以问你一个问题吗?I was really anxious about you. You shouldn’t have left home without a word. 你真急死我了。
你不该一句话也不说就离开家。
注意:have to 的疑问和否定是借助于do来构成。
Do you have to go out today?今天你得出去吗?He doesn’t have to go.他没必要去。
四、情态动词的基本用法1、can和could(1)表能力①意为“能够会”,表示体力或脑力等方面的能力Some of us can use the computer now , but we couldn't ten years ago.现在我们一些人能用计算机了,但十年前我们不能。
Can you ride a bike?你能骑自行车吗?What can I do for you?我能为你做点什么?I could run faster then. 我那时能跑得更快一些。
②当can和could表示能力时,有时可以用be able to替换,could表过去,can表现在,有时也可表将来,但不能与will, shall等助动词连用;be able to可以用于将来、完成等时态。
She hasn't been able t o come to school for three days.她已经三天没能来上学了。