Unit2SectionⅢGrammar——情态动词Ⅱ

1、Section Grammar 情态动词 () 语 境 自 主 领 悟先观察原句后自主感悟By now his restaurant ought to be full of people.Does your father need any help?What do we need to take for thepicnic? There is enough time.Youneednthurry.His mother is ill.He has tostayathometolook after her.Somethingterriblemust havehappened if Li Chang

2、 was not coming to eat in his restaurant as he always did.1.以上句子中，句中的黑体词都是情态动词，而句中的黑体词是实义动词。2以上各句中的情态动词后都接动词原形。其中句中must havehappened的意思是“一定已经发生了”。3上述句子中 ought to 意为“应该”； need意为“需要”； has to意为“不得不”。 语 法 精 要 点 拨一、 ought to的用法1“应该”，表示责任或义务。用于表示按道理应当，常指客观的义务或责任，大多数情况下可用should 代替，但比 should 语气重。You ought t

3、o study harder than your brother.你应该比你哥哥更努力学习。I shouldhelp her because she is in trouble.她有困难了，我应该帮助她。2“应该”，表示劝告、建议或命令。should 和 ought to 可通用，但在疑问句中常用 should。ought to 的否定式为 oughtnt to 或 ought not to。You ought to balance career and family.你应该平衡好事业与家庭之间的关系。Should I open the window?我可以打开窗户吗？3“应该”，表示推测。可

4、与should 换用。Mary ought to be here soon.玛丽应该很快就来了。第 1页This is where the oil ought to/shouldbe.这里应该就是石油存在的地方。即时训练 1用 ought to 补全句子下次过马路时，你应该更小心些。You ought to be more careful when you cross the road next time.你不该责备他。You oughtnt/ought not to scold him.我应该明天动身吗？是的，你应该。Ought I to leave tomorrow?Yes，you oug

5、ht to二、 have to的用法have to 意为“不得不”，有时态、人称和数的变化，其否定形式和疑问形式需要借助于助动词do。It was raining outside； we had to stay at home.外面下雨了，我们不得不待在家里。 考点警示 have to，must(1)两者都可意为“必须， 应该”，但 have to 表示客观的需要， 而 must 表示说话人主观上的看法，即主观上的必要。(2)have to 有人称、数和时态的变化，而must 只有一种形式。He had to look after his sister yesterday.昨天他不得不照顾他的

6、妹妹。(3)在否定结构中， dont have to表示“不必”； mustnt 表示“禁止， 不许”。You dont have to tell him about it.你不必把此事告诉他。(4)在回答 must 的一般疑问句时，肯定式常用must，表示“必须”，否定式常用 need not(neednt)或 dont have to，表示“不必”。即时训练 2完成句子 (每空 1 词)他没有钱，只好放弃这个计划。第 2页He had no money， so he had to give up this plan.你千万不能告诉他这个秘密。You mustnt tell him the

7、secret.(3) 我们必须今天下午交作业吗？不，你不必。Must we hand in our homework this afternoon?No， you dont have to三、 need的用法(1)need 作情态动词时，后跟动词原形，表示“需要，有必要”，无人称和数的变化，多用于否定句、疑问句或条件句中。You neednt go there now你.不必现在去那儿。Need I go there now？我现在需要去那儿吗？ 考点警示 由 need 引导的一般疑问句的肯定回答常用must 或 have to，否定回答常用 neednt。Need I hand in my

8、paper now?Yes，you must./No，you neednt.我现在需要交上论文吗？是的，你必须。 /不，你不需要。(2)作为实义动词，同其他实义动词一样，可用于各种句式，有时态、人称和数的变化，构成否定句和疑问句时要借助于助动词do。You need to be careful.你得小心些。You dont need to be so worried.你不必如此担心。 名师点津 当 need 作实义动词 “需要 ”讲时 ，其后跟不定式的被动形式，相当于跟 v.- ing 的主动形式 ，在这一点上 ，与 want 和 require 作 “需要 ” 讲时用法一样。The hous

9、e needs/wants/requires repairing/to be repaired.这所房子需要修葺。第 3页即时训练 3完成句子我的房间很乱，但今晚出去之前我不需要打扫，我会早晨打扫的。My room is in a mess， but I neednt clean it before I go out tonight.I can do it inthe morning.我需要留下来帮他们吗？是的，你必须留下来。不，你不必。Need I stay to help them?Yes，you must /No，you neednt四、情态动词 have done“情态动词 have

10、done”表示对过去事情的推测。 各情态动词的这种具体用法如下表：can/could have done1.过去可能 (表推测 )2本能做而未做 (表虚拟 )should/ought to have done本该做而未做may/might have done1.过去也许做了 (表推测 )2本可能做而未做 (表虚拟 )must have done一定已经做了neednt have done本不必做而做了From what you said， she must have toldyou all about it.从你所说的来看，她一定把一切都告诉你了。You should have toldme

11、earlier or I might have gonewith them.你应该早点告诉我，不然的话我就会和他们一块去了。They could have sent upthe satellite successfully.他们本来有能力成功发射这颗卫星的。You ought to/should have beenmore careful.你本应该更小心一些的。You neednt have toldthem about it.你本来没有必要告诉他们那件事。即时训练 4完成句子第 4页我从未玩得更开心过 这是完美的一天。I couldnt have enjoyed myself moreit

12、was a perfect day.他们本应该在午饭时间就到达的，但是他们的航班被耽搁了。They should have arrived at lunchtime but their flight was delayed.【导学号： 65162019】迈克本来不必那么匆忙的。全速驾驶之后，他早半个小时到达了。Mike neednt have hurriedAfter driving at top speed ，he arrived half an hourearly. 语 法 应 用 落 实.用适当的情态动词填空1You ought to/should have given(give) hi

13、m some advice.He was too upset atthat time.2. You mustnt smoke(smoke) in this part of the hospital.3. There was plenty of time.She neednt have hurried(hurry)4. I have no bike，so I have to go(go) to the office on foot.5. You neednt buy(not buy) a gift，but you can if you want to.6. Look! The road is w

14、et.It must have rained(rain) last night.7. Bob ought not to speak(not speak) to his mother like that.8You must come(come) here on time，or youll be fined next time.9Hurry up! We ought to/should go(go) to school right away.10 Her eyes are red.She must have been(be) crying.完成句子1I have just found that I

15、 have to attend an important class meeting(我必须参加一个重要的班会 ) that afternoon.2The length of the article should be limited to 400 words or so(应当限制在 400词左右 )3The last important thing you should remember( 你应当记住的是 )is that you have to send the article to me before June 28.4George cant have gone不(可能走 ) too f

16、ar.His coffee is still warm.第 5页5I love the weekend，because I neednt get up early (不必早起 )on Saturdaysand Sundays.6Why didnt you tell me about your trouble last week ？ If you had told me ，Icould have helped(就可能帮你了 )7Sorry，Mum ！ I failed the job interview again.Oh，its too bad.You should have made fullpreparations(本应该做充足的准备 )8I neednt ha