Unit2HealthyLifestyleDiscoverUsefulStructures不定式作主语课件-高中英语人教版选择性

选择性必修三Unit2HealthyLifestyleDiscoverUsefulStructures不定式作主语mastertheusageoftheinfinitiveassubject.01usetherelevantgrammarflexiblyandauthenticallyinrealsituation.02understandthedifferencebetweentheinfinitiveassubjectandV-ingformasthesubject.03LearningObjectives不定式todo作表语结构S+betodo形式用法（1）表示主语的内容。（2）表示事态发展预期的结果、不幸的命运等。（3）用于第一人称疑问句，表示征求意见。（4）表示“同意、安排、命令、决定、劝告、意愿、禁止”等。常见情况（1）主语常是表示方式、目的、计划、梦想、责任等的词，如way,intention,purpose,aim,attempt,plan,duty,dream等。（2）what引导的名词性从句。（3）当主语有all,或者主语被序数词、或theonly,thelast或形容词最高级修饰时，其后可接“系动词+不定式”作表语。省略to前有do,后省toReviewUnit1不定式todo作表语1.不定式(短语)置于句首作主语2.it作形式主语3.动词不定式作主语时的语态4.todo和doing作主语的区别单个2个或以上谓语动词：单数语义一致：单数语义不一：复数Ittakessb.time/money/energytodosth.Itis+adj.+（for/ofsb.）todosth.Itis+n.+(forsb.)todosth.经常性/习惯性/抽象性具体的、一次性的或将来的tododoingPreviewLead-inLookatthefollowingsentencesandpayattentiontotheitalicisedinfinitives.Findmoreinfinitivesinthereadingpassage.Inpairs,discusstheirmeaningsandfunctions.1Tochangebadhabitsisnevereasy.2Ittookthesurgeon(n.外科医生)threehourstofinishmymother’slungsurgery(n.外科手术).3TojointhePeople’sLiberation(n.解放)Army,itisrequiredformentoshaveoff(剃掉,刮掉)theirbeards.4Itwasnotpolitetodisturb(v.打扰)yourneighbourswithloudmusiclastnight.主语主语主语主语状语Presentation1Exploregrammar-不定式(短语)置于句首作主语Tosee

istobelieve.Togetupearly

isnecessary.Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.(para1)Summary11.不定式作主语通常位于______，表示具体的某次动作，谓语动词用______。注意：当句子主语和表语都是非谓语时，通常要保持一致。句首单数Exploregrammar-不定式(短语)置于句首作主语1.TolearnEnglishwellandtomasteraskill_______(be)veryimportantforyourfuture.2.Tojogeverymorningandtodosomestretchingexercisesintheevening_______(be)goodwaystokeepfit.两个或两个以上的不定式作主语时：若语义_________或不定式_____________，谓语动词用_____；若语义不一致，则用______。3.Toloveandtobeloved_____sweettous.areareisSummary2基本一致作为一个整体单数复数Presentation1Exploregrammar-不定式(短语)置于句首作主语Summary3________(怎样)tohandletherubbishisthequestion.________(去哪)togofordinner

hasnotbeendecided.HowWhere1.________和动词不定式构成不定式短语作主语2.可用于该结构的疑问词疑问代词:疑问副词:疑问词who,whom,what,whichwhen,where,how①Whenandwhere________

(vote)hasn’tbeendecided.②______________（何时装修）thehousehasn’tbeendecidedWhentodecoratetovotePresentation1Exploregrammar--it作形式主语Itisimportanttokeepabalanceddietanddoexerciseregularly.​

Tokeepabalanceddietanddoexerciseregularlyisimportant.主语动词不定式作主语时，若不定式太长，为避免头重脚轻，常用it作形式主语，将真正的主语置于后面。Presentation2Summary1Itis＋adj.＋(for/ofsb)todosth.(对某人来说)做某事是……①Itis＋adj.

＋for

sb.todosth.表示的是_____________________________用于此句型的形容词有：________________________________________________________________________________________________________________________easy, hard,difficult,possible,important,essential,impossible,necessary, good,bad,exciting,interesting,surprising,inconvenient等。Itisimportant

forustodrinkenoughwater.​Itisdifficult

forustofinishwritingthecompositioninaquarterofanhour.事物或行为的特点或性质sb.是todosth.的逻辑主语Exploregrammar--it作形式主语Presentation2Summary1Itis＋adj.＋(for/ofsb)todosth.(对某人来说)做某事是……②Itis＋adj.

＋of

sb.todosth.表示的是_______________________________________用于此句型的形容词有：________________________________________________________________________________________________________________________pity,shame,pleasure,one’sduty,one’sjob, fun,joy,goodmanners,badmanners,careless,clever,kind,foolish,honest,impolite,lazy,wise等Itisimpolite

ofyoutodisturbothers.Itwasfoolish

ofhimtomakesuchamistake.不定式的逻辑主语的性质、身份、特点sb.是todosth.的逻辑主语Exploregrammar--it作形式主语Presentation2Summary2Itis＋n.＋（forsb.）todosth.做某事是……常见的名词有：________________________________________________________________________________________________________________________pity,shame,pleasure,one’sduty,one’sjob, fun,joy,goodmanners,badmanners等Itisahardtasktochangelonghabitsinashorttime.Itisadoctor’sdutytohealthewoundedandrescuethedying.Exploregrammar--it作形式主语Presentation2Summary3Ittakes/took/willtakesb.time/money/energytodosth.花某人时间/金钱/精力做某事1.Ittakesme

30minutes

todoyogaeveryevening.2.Ittookhim

lotsofenergytoclimbthemountain.3.Itwilltakethem

somemoneytobuysportsequipment.Exploregrammar--it作形式主语Presentation2小结it作形式主语代替真正主语不定式常见于以下情况中：Itis+adj.+for/ofsb.todosth.Itis+n.+(forsb.)todosth.Ittakes/took/willtakesb.time/money/energytodosth.Exploregrammar--it作形式主语Presentation2Presentation3Exploregrammar--动词不定式作主语时的语态Summary动词不定式作主语时,如果不定式和逻辑主语之间是主动关系应使用todo,如果是被动关系应使用_________。

①Itwasanhonourforhimtobechosenasheadofthemedicalteam.②Tofinishthetaskwilltakealongtime.

tobedonePresentation3Exploregrammar--动词不定式作主语时的语态Summary动词不定式作主语时,如果不定式和逻辑主语之间是主动关系应使用todo,如果是被动关系应使用_________。

①Itwasanhonourforhimtobechosenasheadofthemedicalteam.②Tofinishthetaskwilltakealongtime.

tobedone类别主动形式被动形式时间一般式

完成式进行式tobedonetohavedonetobedoingtohavebeendone发生在谓语动词之后发生在谓语动词之前正在进行todoPresentation4Exploregrammar--不定式作主语和动词-ing形式作主语的区别Summary动名词作主语表示______________________的行为;不定式作主语表示_________________________

动作。①Tohavean8-hoursleepismyplantoday.②Havingan8-hoursleepismydailyroutine.经常性/习惯性/抽象性具体的、一次性的或将来的1.______(do)morningexercisesregularlyisgoodforyourhealth.

2.Itfeelsreallygood______(do)morningexercisestoday.Doingtodo不定式todo作表语1.不定式(短语)置于句首作主语2.it作形式主语3.动词不定式作主语时的语态4.todo和doing作主语的区别单个2个或以上谓语动词：单数语义一致：单数语义不一：复数Ittakessb.time/money/energytodosth.Itis+adj.+（for/ofsb.）todosth.Itis+n.+(forsb.)todosth.经常性/习惯性/抽象性具体的、一次性的或将来的tododoingSummaryNotice不定式短语作独立成分

tobegin/startwith首先

tosumup总而言之

toconclude总而言之

totellthetruth说实话

tobefrank坦白地说

tobehonest说老实话tobebrief简言之

一些不定式短语可用作独立成分，通常位于句首，有时位于句中或句末，要用逗号同其他句子成分隔开。Totellthetruth，Idon’tlikethegiftedactressinthemovie.说实话，我不喜欢这部影片中的那个有天赋的女演员。（1）

（总而言之），mostofthecommitteememberssupportedtheideabutafewwereagainstit.（2）

（简言之），hewashappywiththeresult.（3）Shewrote，

（确切地说），tennovelsinherlifetime. （4）

（首先），he’stooyoungforthatkindofjob.（5）

（说老实话），Idon’treallywanttogotothepartytonight.Tosumup/ToconcludeTobebrieftobeexactTobegin/startwithTobehonestPracticeJointhewordstomakefullsentences,andthenjointhesentencestomakeaparagraph.Youcanaddyourownsentencesifnecessarytomakeyourparagraphmoremeaningful.1.important/avoid/passivecigarettesmokingItisimportanttoavoidpassivecigarettesmoking.2.willtake/nutritionspecialist/abalanceddietmenu/make/anhour/foryou3.useful/turnto/fitnessconsultant/foradviceItwilltakeanhourforanutritionspecialisttomakeabalanceddietforyou.Itisusefultoturntothefitnessconsultantforadvice.4.illegal/dangerous/takedrugs5.harmful/skipbreakfast/oftenItisdangeroustotakeillegaldrugs.Itisharmfultoskipbreakfast(too)often.PracticeCompletetheconversationswiththecorrectformsofthephrasesinthebox.1.A:Hello,doctor.Iwanttoloseweight,butIjustcan’tseemtodoit.Whatcanyoudotohelpme?B:Well,first,it’snecessaryto________________whatyoueat.Cutoutallfattyfoodandsugarydrinks,andeatmorefruitandvegetables.2.A:Ireallyneedto____________awaytoexercisemore.Icoulduseafitnessapp,butmyphone’sfull.B:Sodeleteafewfiles.I’msuretheappdoesn’ttakeupmuchspace.beincontrolofbeginwith,beincontrolof,makeachoice,decideon,makeupone’sminddecideonPracticeCompletetheconversationswiththecorrectformsofthephrasesinthebox.beginwith,beincontrolof,makeachoice,decideon,makeupone’smind3.A:Beforeexercising,alwaysdoafewwarm-upsto___________.B:Iknow.ButthenIalwaysfeeltootiredtocontinue!beginwith4.A:ShouldIgoforthepizzaorthefriedchicken?Ihate_________________likethese.Youknowwhat—I’mgoing