【課件】Unit 2 Discover useful structrues語(yǔ)法精講課件-高中英語(yǔ)人教版（2019）選擇性必修第三冊(cè)

語(yǔ)法精講Unit2

TheInfinitive

(todo……)不定式的時(shí)態(tài)和語(yǔ)態(tài)不定式主動(dòng)被動(dòng)

一般towritetobewritten

進(jìn)行tobewriting

完成tohavewrittentohavebeenwritten

完成進(jìn)行tohavebeenwriting

4.Itisimportant

______Tomtogetthatjob.Itiskind______youtohelpmewithmyhomework.

1.______(talk)withhimisagreatpleasure.2.______(help)othersisourduty.TotalkTohelpItisourdutytohelpothersforof3.Itiseasy______________________(學(xué)生讀)forthestudentstoread.Lookatthefollowingsentencesandpayattentiontotheitalicisedinfinitives.Findmoreinfinitivesinthereadingpassage.Inpairs,discusstheirmeaningsandfunctions.1Tochangebadhabitsisnevereasy.2Ittookthesurgeon(n.外科醫(yī)生)threehourstofinishmymother’slungsurgery(n.外科手術(shù)).主語(yǔ)主語(yǔ)3TojointhePeople’sLiberation(n.解放)Army,itisrequiredformentoshaveoff(剃掉,刮掉)theirbeards.4Itwasnotpolitetodisturb(v.打擾)yourneighbourswithloudmusiclastnight.目的狀語(yǔ)主語(yǔ)主語(yǔ)Moresentencesinthereadingpassage:1.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.2.Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.3.Tochangebadhabitsisnevereasy,evenwithmanyattempts.4.Afterall,itisnoteasytobreakbadhabits.動(dòng)詞不定式作主語(yǔ)常見(jiàn)的三種形式1.不定式作主語(yǔ)通常位于句首，表示具體的某次動(dòng)作，謂語(yǔ)動(dòng)詞用單數(shù)。e.g.Toseeistobelieve.百聞不如一見(jiàn)。Togetupearlyisnecessary.早起是必要的。Tolearnaskillisveryimportantforeveryoneinsociety.?學(xué)習(xí)一項(xiàng)技能對(duì)社會(huì)上的每個(gè)人都很重要。Tofinishthebuildinginamonthisdifficult.要在一個(gè)月內(nèi)完成這座建筑是困難的。2.動(dòng)詞不定式與疑問(wèn)詞who,whom,whose,what,which,when,

where,how等連用構(gòu)成不定式短語(yǔ)，也可作主語(yǔ)。

e.g.Howtousethecomputeristhequestion.如何使用計(jì)算機(jī)是個(gè)問(wèn)題。Wheretogohasnotbeendecided.去哪兒還沒(méi)有定下來(lái)。3.當(dāng)主語(yǔ)較長(zhǎng)，謂語(yǔ)較短時(shí)，常用it作形式主語(yǔ)放在句首，而將真正的主語(yǔ)—不定式放到謂語(yǔ)的后面。e.g.It’snoteasytoworkouttheproblem.=Toworkouttheproblemisnoteasy.計(jì)算出這道題不容易。Itisinterestingtoplaywithsnowinwinter.冬季里玩雪是很有趣的。Itisterribletoseetheshipsinkingintothesea.目睹輪船沉入大海，真是太可怕了。it作形式主語(yǔ)代替真正主語(yǔ)不定式常見(jiàn)于以下情況中：Itis+adj.+for/ofsb.todosth.Itis+n.+(forsb.)todosth.Ittakes/took/willtakesb.sometime/moneytodosth.【溫馨提示】常用于表示事物的特征，用于此句型的形容詞有：easy,?hard,?difficult,?possible,?important,?impossible,?necessary,?good,?bad,?exciting,?interesting,?surprising等。1)Itis＋adj.

＋forsb.todosth.sb.是todosth.的邏輯主語(yǔ)Itis+adj.+for/ofsb.todosth.e.g.Itisnecessaryforyoungstudentstolearna?foreignlanguage.對(duì)年輕的學(xué)生來(lái)說(shuō)，學(xué)習(xí)一門外語(yǔ)是必要的。Itisnecessaryforyoutochangeyourjob.你有必要換工作。Itwasimpossibleforthemtocompletethetaskinsuchashorttime.他們不可能在這么短的時(shí)間內(nèi)完成這項(xiàng)任務(wù)。It’simportantforustokeepthewaterclean.保持水質(zhì)清潔對(duì)我們來(lái)說(shuō)是很重要的。常見(jiàn)的此類形容詞有：

kind,?nice,?wise,?silly,?polite,?impolite,?friendly,?foolish,?clever等。2)Itis＋adj.＋ofsb.＋todosth.形容詞用來(lái)表示不定式的邏輯主語(yǔ)(sb.)的性質(zhì)、特征或品德e.g.Itwassillyofyoutogiveupsuchagoodchance！

你放棄這么好的一個(gè)機(jī)會(huì)，真傻!It’sverykindofyoutosayso.你這樣說(shuō)真是太好了。Itisfriendlyofthefamilytotrytomakemefeel

athomeintheirhouse.這家人對(duì)我很友好，使我在他們家里感到賓至如歸。Itwasrudeoftheboytojumpthequeue!?那個(gè)男孩插隊(duì)真是太無(wú)禮了!常見(jiàn)的名詞有：pity,?shame,?pleasure,?one’sduty,?one’sjob,?fun,?joy,?goodmanners,?badmanners等。Itis+n.+(forsb.)todosth.e.g.Whatapityitisforyoutohavemissedsuchawonderfulfilm.真遺憾你錯(cuò)過(guò)了這樣一個(gè)精彩的電影。??Itmustbegreatfuntoflytothemooninaspaceship.

乘宇宙飛船飛往月球一定很有趣。Ittakes/took/willtake

sb.sometime/money

todosth.做某事花費(fèi)某人多長(zhǎng)時(shí)間(錢)e.g.Ittookmemorethananhourtodomyhomeworkyesterdayevening.昨天晚上我做作業(yè)用了一個(gè)多小時(shí)。Itwilltakeusalotofmoneytobuythathouse.買那套房子要花費(fèi)我們很多錢。3.如果要說(shuō)明不定式表示的動(dòng)作是誰(shuí)做的，可以在不定式前加一個(gè)由for/of引起的短語(yǔ),構(gòu)成__________。2.不定式作主語(yǔ)時(shí),可以用it作_______________.Itis+adj+forsbtodo……5.Itis+adj+ofsbtodo………(adj:kind,good,nice,wise,unwise,clever,silly,stupid,foolish,careless,rude,polite,naughty)（修飾人品形容詞）（修飾物的形容詞）1.單個(gè)不定式作主語(yǔ)，謂語(yǔ)動(dòng)詞_________單數(shù)形式主語(yǔ)不定式的復(fù)合結(jié)構(gòu)語(yǔ)法總結(jié)(adj.:easy,difficult,comfortable,pleasant,light,dangerous，tiresome,interesting,heavy,fit)Jointhewordstomakefullsentences,andthenjointhesentencestomakeaparagraph.Youcanaddyourownsentencesifnecessarytomakeyourparagraphmoremeaningful.1.important/avoid/passivecigarettesmoking

Itisimportanttoavoidpassivecigarettesmoking.n.香煙2.willtake/nutritionspecialist/abalanceddietmenu/make/anhour/foryouItwilltakethenutritionspecialistanhourtomakeabalanceddietforyou.3.useful/turnto/fitnessconsultant/foradviceItisusefultoturntothefitnessconsultantforadvice.n.專家n.顧問(wèn)4.illegal/dangerous/takedrugs5.harmful/skipbreakfast/oftenItisillegalanddangeroustotakedrugs.Itisharmfultoskipbreakfastoften.n.毒品，藥品v.跳過(guò)Completetheconversationswiththecorrectformsofthephrasesinthebox.1.A:Hello,doctor.Iwanttoloseweight,butIjustcan’tseemtodoit.Whatcanyoudotohelpme?B:Well,first,it’snecessaryto________________whatyoueat.Cutoutallfattyfoodandsugarydrinks,andeatmorefruitandvegetables.beincontrolofbeginwith,beincontrolof,makeachoice,decideon,makeupone’smind2.A:Ireallyneedto____________awaytoexercisemore.Icoulduseafitnessapp,butmyphone’sfull.B:Sodeleteafewfiles.I’msuretheappdoesn’ttakeupmuch