高中英語必修三 Unit 5 The Value of Money 5.2 Discovering Useful Structures

1、Unit 5 The Value of MoneyDiscovering Useful Structures2Read and pay attention to the words in bold. Step 1. Lead in情態(tài)動詞表示說話人對某一動作或狀態(tài)的態(tài)度，本身不能單獨(dú)作謂語，必須和不帶to的不定式(即動詞原形)連用。情態(tài)動詞沒有人稱和數(shù)的變化。一、情態(tài)動詞Step 2. Presentation1.can和could (could是can的過去式，語氣更委婉)合作探究1能力許可可能可能性可能再也不為過can表示推測。can表推測時一般用于否定句和疑問句中(could一般無此限制

2、)。表示對過去發(fā)生的行為懷疑或不肯定時, 常用“can/could+have+過去分詞”的否定或疑問形式。It cant/couldnt be true. 那不可能是真的。Can/Could he have heard the news? 他聽說過這個消息了嗎? can表示客觀的、一時的情況, 意思是“有時候會”。The weather in Shanghai can/could be very cold in winter. 上海冬季可能很冷。表示驚異、懷疑, 不相信的態(tài)度(主要用在否定句、疑問句或感嘆句中)。How can you be so careless! 你怎么那么粗心呀! 2.m

3、ay和might合作探究2May I play computer games after supper?Yes，you may./No，you mustnt.They may/might be having a meeting，but Im not sure.If you are interested，you may/might as well try.自主發(fā)現(xiàn)2(1)句中may表示_。否定回答時，用_。(2)句中may和might表示_，_可能性更小。(3)句中_，意為“不妨”。允許或征詢對方許可mustnt可能性mightmay/might as well動詞原形3.must與have t

4、o合作探究3I have to wait until the rain stops because I have no umbrella with me.我不得不在這兒等到雨停，因為我沒帶傘。(強(qiáng)調(diào)客觀需要)I must recite the text this morning.今天早上我必須背會這篇課文。(強(qiáng)調(diào)主觀意志)Must we hand in our homework today?Yes，you must./No，you dont have to/you neednt.You mustnt smoke here.Your mother must be waiting for you

5、now.你的母親現(xiàn)在一定在等著你。Why must you always interrupt me？你為什么非要一直打斷我呢？自主發(fā)現(xiàn)3(1)句中have to和句中must均表示“_”，但_是指說話人的主觀看法，而_則強(qiáng)調(diào)客觀需要。(2)句中must 所構(gòu)成的疑問句，回答的否定形式通常為_或_，意為“不必要”，而一般不說_ (句中mustnt表示“禁止”)。(3)_句中must 常表示有根據(jù)的、比較確定的推測(只用于肯定的陳述句)，譯為“一定，必定”。(4)句中must表示“_”。,必須musthave toneedntdont have tomustnt偏要，偏偏4.should和ough

6、t to合作探究4All visitors should/ought to take the tickets and masks.I find it astonishing that he should be so rude to you.他竟然對你這樣無禮，真讓我吃驚。Mr Lee asked if he should get his visa on time.李先生問能否按時拿到簽證。自主發(fā)現(xiàn)4(1)句中should表示“_”，其同義詞是_；在疑問句中，通常用_代替ought to。(2)句中should 有時可用于某些從句中，表示說話人驚奇、失望等感情色彩，常譯為“竟然，怎么會”。(3)

7、句中should作為shall的過去式，用于第一、三人稱作主語的疑問句，且多用于間接引語中，以征求對方的意見。義務(wù)、責(zé)任、建議ought toshould5.will和would合作探究5Would you pass me the coffee，please？She said that she would try her best to help the patients.Each time his mothers birthday came，he would buy her a present.每次到他母親生日的時候，他都要給她買一件禮物。(表示過去的習(xí)慣)We will do our be

8、st to help the homeless child. Oil will float on the water.油總是浮在水面上。自主發(fā)現(xiàn)5(1)句中would表示_，比will更委婉客氣。(2)句中would和句中的will表示_。(3)句中would和句中的will表示習(xí)慣性動作或客觀真理。would表示過去的習(xí)慣性動作時，暗示現(xiàn)在仍然如此；而used to表示過去常常做某事，強(qiáng)調(diào)現(xiàn)在不是這樣了。My father used to go to the office by bike when he was young.我父親年輕的時候總是騎自行車去上班。(現(xiàn)在不是這樣了)請求、建議意志

9、、愿望和決心6.dare合作探究6If he dare go，Ill go with him.如果他敢去，我就跟去。Tom didnt dare to break the rules.自主發(fā)現(xiàn)6(1)dare作情態(tài)動詞時，表示“敢，敢于”。常用于否定句和疑問句中，后接動詞原形，否定形式為dare not。(2)dare常用作實義動詞，有時態(tài)、人稱和數(shù)的變化，后面可接帶to的不定式。7.had better合作探究7You had better ask the teacher for help. You had better not talk with strangers.你最好不要和陌生人講話

10、。自主發(fā)現(xiàn)7had better表示“_”，使用時?？s寫為_，無人稱和數(shù)的變化，其否定式一般把not放在had better之_。最好d better后二、過去將來時1. 過去將來時表示從過去某一時間來看將要發(fā)生的動作或存在的狀態(tài), 常用在賓語從句中。一般由“would/should +動詞原形”構(gòu)成。She hoped that they would meet again someday. 她希望將來有一天他們能再見面。I rang up to tell my father that I should leave for London. 我打電話告訴我父親我要去倫敦。2. was/were

11、going to+動詞原形: 表示過去將要發(fā)生或很有可能發(fā)生的動作, 常用于口語中, 表示預(yù)言、意圖或者打算等。He was going to start work the following week. 他打算下星期開始工作。Alice, why didnt you come yesterday? 愛麗絲, 你昨天為什么沒來呀? I was going to, but I had an unexpected visitor. 我打算去的, 但我家來了個不速之客。3. was/were about to do: 常用來表示即將發(fā)生的動作, “剛要/正要做”。注意該結(jié)構(gòu)不與任何時間狀語連用。I

12、felt that something terrible was about to happen. 我感到某種可怕的事情即將發(fā)生。We were about to go there when it began to rain. 我們剛打算去那兒, 這時天下起了雨。4. start, go, come, leave, see, meet等動詞的過去進(jìn)行時: 表示就過去某一時刻而言即將發(fā)生的動作。She was coming later. 她隨后就來。I had just put on my overcoat and was leaving to visit a friend of mine. 我

13、剛穿上外套要去看我的一個朋友。5. was/were to do: 表示“曾計劃做某事”, 如果表示“本來計劃做某事, 動作沒實現(xiàn)”, 則需用 “was/were to have done”。She said she was to have told me about the accident. 她說她本來想告訴我關(guān)于事故的事。He said he was to meet his friend at the station at 4 p. m. 他說他下午四點(diǎn)去車站接他的朋友。1(1)選詞填空：can，could，couldnt，be able toSamuel，the tallest boy

14、 in our class，_ easily reach the books on the top shelf.It was really annoying; I _ get access to the data bank you had recommended.It was so noisy that we _ hear ourselves speak. _ I have a word with you? It wont take long.cancouldnt couldntCanStep 3. Practice(2)補(bǔ)全句子I _ for your kindness.我再怎么感謝你的好意

15、也不為過。Keep working on it! You _ for the exam.繼續(xù)努力！準(zhǔn)備考試再充分也不為過。cannot thank enoughcant prepare too much2(1)用適當(dāng)?shù)那閼B(tài)動詞填空You _ feel all the training a waste of time，but Im a hundred percent sure later youll be grateful you did it.Life is unpredictable; even the poorest _ become the richest._ I smoke in th

16、is room?No，you _.(2)補(bǔ)全句子I neednt wait，I _ you now.我不必等了，不妨現(xiàn)在就告訴你。maymightMaymustntmay/might as well tellStep 3. Practice3選詞填空：must，neednt，have to，mustntCant you stay a little longer?Its getting late.I really _ go now.My daughter is home alone.You _ be careful with the camera.It costs!_ I turn down t

17、he radio now?No，you _.My brother was ill，so I _ call a doctor in.mustmustMustneednthad toStep 3. Practice4補(bǔ)全句子It was sad to me that they，so poor themselves，_.他們這么窮竟然還帶食物給我，這使我很難過。You _ the baby to the doctors.你應(yīng)該把這嬰兒帶去看看醫(yī)生。I asked the teacher if I _.我問老師我能否請一天假。should bring me foodshould takeshould

18、have one day offStep 3. Practice5選詞填空：would，used toI still remember my happy childhood when my mother _ take me to Disneyland at weekends.Whenever I was in trouble，he _ help me.If I write a letter，_ you post it for me?I _ drink coffee，but now I drink green tea.wouldwouldwouldused toStep 3. Practice6

19、補(bǔ)全句子He _ say what he thought.他不敢說出他的想法。_ staying where she was?她還敢冒險呆在原來的地方嗎？didnt dare (to)/dared notDare she risk7補(bǔ)全句子Its half past two.I think we _.現(xiàn)在兩點(diǎn)半了。我想我們最好還是回家吧。You _ class any more.你最好不要再上課遲到了。had better go homehad better not be late for Step 3. Practice8補(bǔ)全句子I told him I _ at the station.我跟他說，我會到車站去給他送行。The sky went very dark and we thought it _ but it was a false alarm.天空變得黑沉沉的，我們以為要下雨了，不過只