1、Unit 2 Healthy eating,达标检测,语法导学,内容索引,Period Four GrammarModal verbs(),语法导学,阅读以下句子，仔细观察加颜色部分并补全空格。 1.By now his restaurant ought to be full of people. 2.Does your father need any help? 3.What do we need to take for the picnic? 4.You neednt try to explain. 5.His mother is ill.He has to stay at home to
2、 look after her. 6.Something terrible must have happened if Li Chang was not coming to eat in his restaurant as he always did.,1.以上句子中，第 句中的加颜色词都是情态动词，而第 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。其中第6句中must have happened的意思是“ ”。 3.上述句子中ought to意为“ ”；need意为“ ”；has to意为“ ”。,1、4、5、6,2、3,一定已经发生了,应该,需要,不得不,1.ough
3、t to的用法 (1)表示责任和义务，意为“应该”，与should同义。 You ought to be more careful when you do some shopping on the Internet. 在网上购物时，你应该更小心些。,考点警示 ought to的否定形式为ought not to/oughtnt to，一般疑问形式是将ought提至句首，其否定答语通常用dont have to或neednt。 You ought not to make this kind of mistake again. 你不应该再犯这种错误了。 Ought he to see the do
4、ctor? Yes，he ought (to)./No，he doesnt have to/neednt. 他该去看医生吗？ 是的，他该去。/不，他不必去。,(2)表示可能性，一般指较大的可能性，意为“按道理应该”。 If he started at six，he ought to be here now. 要是他六点就出发的话，这会儿该到这里了。,2.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. 下雨了，我们不得不待在家里。
5、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. 昨天他必须照顾他的妹妹。 My sister is ill；my mother has to look after her. 我妹妹生病了，妈妈不得不照顾她。 We must help each other.我们必须互相帮助。,(3)在否定结构中，dont have to
6、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。 You mustnt point at others with chopsticks. 你不许用筷子指着别人。 (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”。,3.need的用法 (1)need既可以作实义动词，也可以作情态动词。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
7、neednt go there now.你现在不必去那儿。 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 paper now? Yes，you must/have to./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、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。 Yo
8、u dont need to be so worried.你不必如此担心。 考点警示 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”讲时一样。 The house needs/wants/requires repairing/to be repaired. 这所房子需要修葺。,4.dare的用法 (1)dare既可以作实义动词，也可以作情态动词。作情态动词时多用于疑问句、否定句、条件状语从句以及表示怀疑的名词性从句中，表示“敢”。 I dare not walk through the wood at n
9、ight. 夜间我不敢在小树林里走。 (2)dare作实义动词时，在否定句中不定式符号to也可以省略。 The children dont dare (to) make a sound while their parents are sleeping. 孩子们在父母睡觉时不敢弄出一点声音。,5.“情态动词have done”结构的用法 (1)must have done表示对过去发生的事情所作出的合理或很有把握的推测，意为“想必/准是/一定”，只用于肯定句中，在否定句或疑问句中通常被can/canthave done代替。 From what you said，she must have to
10、ld you all about it. 从你所说的来看，她一定把一切都告诉你了。,(2)can have done一般用于疑问句和否定句中，用于表示对过去所发生事情的推测。could have done用于肯定句时，表示“可能已经做过某事”或“本有能力做某事而未做”。 Mr Smith cant have gone to Beijing，for I saw him in the library just now.史密斯先生不可能去北京了，因为我刚才还在图书馆看见他了。,(3)should/ought to have done表示“过去本应该做某事而(实际上)没有做”，含有责备或遗憾的语气；其
11、否定形式表示“某种行为不该发生却发生了”。 You should have done more exercise before. 以前你应该多进行锻炼的。 (4)need have done表示“本需要做而实际未做”；neednt have done表示“本不必做某事而实际做了”。 As it turned out to be a small house party，we neednt have dressed up so formally. 原来是一个小型的家庭聚会，我们本来没必要穿得那么正式。,(5)may/might have done表示对过去发生的事情的推测，意思是“也许已经做了某事
12、，可能已经做了某事”，多用在肯定句中，用might时表示语气更加不肯定。 You might have read about the news in the papers. 你可能已经在报上看过这个消息了。,用适当的情态动词的肯定或否定形式填空 1.I cant find my purse.I have left it in the supermarket yesterday，but Im not sure.(2018天津) 2.My room is a mess，but I clean it before I go out tonight.I can do it in the morning
13、.(2017天津) 3.George have gone too far.His coffee is still warm.(2016浙江),could/might,neednt,cant,答案,4.I have worried before I came to the new school，for my classmates here are very friendly to me.(2015天津) 5.Sorry，Mum! I failed the job interview again. Oh，its too bad.You have made full preparations. (2
14、015福建) 6.My book，The House of Hades，is missing.Who have taken it？ (2014陕西) 7.Since nobody gave him any help，he have done the research on his own.(2013新课标全国),答案,neednt,should,could,must,达标检测,.选词填空 1.As there was no bus，we (had to；should) walk home. 2.I want to go to the office，but you (need not to go
15、；need not go) with me. 3.I ought (to have taken；to take) those books to the library last week. 4.The mother told her son，“You (wouldnt；mustnt) eat with your fingers！” 5.He went on foot，but he (ought have gone；should have gone) by bus.,had to,need not go,to have taken,mustnt,should have gone,.单句改错(每小
16、题仅有1处错误) 1.You ought keep a simple first aid box at home for any accidents.2.The manager is so hot-tempered that I dare not to tell him the bad news. 3.You neednt to fetch four；two will do.,或You ought keep a simple first aid box at home for any accidents.,should, to,4.They would have arrived at lunchtime but their flight was delayed. 5.You neednt had told me the news.I have already known it.,have,should,
