LearningAboutLanguageDiscoverusefulstructures

動詞不定式作主語Infinitivesasthesubject

LearningAims

Afterthisperiod,studentswillbeableto:1.Tomastertheuseoftheinfinitiveassubject;2.TounderstandthedifferencesoftheInfinitiveandthegerund（動名詞）assubject;3.TousetheInfinitiveassubjectindifferentsituations.Part1Lead-in人教版·高中英語選必修第三冊Revision不定式的形式Differentformsofinfinitive.類別主動語態被動語態意義一般式todo完成式進行式/完成進行式/tobedonetohavedonetobedoingtohavebeendoingtohavebeendone發生在謂語動詞之后發生在謂語動詞之前正在進行一直持續1.基本形式:todo

2.否定形式:not

todo3.沒有人稱和數的變化，但有時態、語態的變化。可作主語、賓語、狀語、表語、定語和補語。LeadinginWatchandthinkWatchashortvidoe,andpayattentiontowhattheysay.WarmingupIt’sdifficultformetogetupearly.Togetupearlyisdifficultforme.主語InfinitiveasSubjectIt

isdifficultformetogetupearly.Itiskindofyoutohelpme!Togetupearly

isdifficultforme.Tohelpmeiskindofyou!todo

作主語動詞不定式（短語）作主語位置直接放在________作主語；為了保持句子平衡，用________作形式主語，放在句首，把真正的主語—動詞不定式置于句后；句首it直接放在________作主語；為了保持句子平衡，用________作形式主語，放在句首，把真正的主語—動詞不定式置于句后；和_________構成“疑問詞+todo”短語作主語。句首it疑問詞動詞不定式作主語有三種形式：Summary1.Tochangebadhabits

isnevereasy.2.Ittookthesurgeonthreehourstofinishmymother’slungsurgery.3.TojointhePeople’sLiberationArmy,itisrequiredformentoshaveofftheirbeards.4.

Itwasnotpolitetodisturbyourneighborswithloudmusiclastnight.2.Payattentiontotheitalicizedinfinitivesanddiscussthemeaningsandfunctionsoftheitalicisedinfinitives.【總結】1.1-4句子中動詞不定式都是作___語。2.句3和句4中it作__________，真正主語是后面的_______。主

形式主語todo

1.Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.2.Tochangebadhabitsisnevereasy,evenwithmanyattempts.3.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.4.Afterall,itisnoteasytobreakbadhabits.5.When

to

go

therehas

not

been

decidedyet.【總結】1.1-4句子中動詞不定式都是作___語。2.句3和句4中it作______，真正主語是后面的_______。3.句5中是______+不定式作主語

主

形式主語

todo疑問詞Part2presentationFocuson基本用法不定式作主語一、通常用法：直接位于句首二、*it作形式主語的用法*it作形式主語時的三種情況三、“疑問詞+動詞不定式”作主語四、不定式和V-ing作主語區別五、不定式作獨立成分Tobeworkingalldaylongisabore.整天干活使人厭倦。(不定式進行式)Tohaveknownyouisaprivilege.認識了你真是榮幸。(不定式完成式)Togetupearlyisnecessary.早起是必要的。1.不定式作主語通常可直接位于句首，表示具體的、某一次的或將來的動作，謂語動詞常用單數。Analysing:infinitiveusedassubject單個不定式作主語，謂語動詞用_______兩個或兩個以上的不定式作主語，若語意一致或作為一個整體，謂語動詞用_______兩個或兩個以上的不定式作主語，若語意不一致，謂語動詞用________單數單數復數動詞不定式（短語）作主語的主謂一致原則：單個動詞不定式（短語）作主語，謂語用單數。ToimproveEnglish

(be)themosturgentthingformenow.兩個或兩個以上的動詞不定式（短語）作主語，若語義一致或基本一致，或動詞不定式（短語）作為一個整體，謂語用單數。Toloveandtobeloved

(be)sweettous.兩個或兩個以上的動詞不定式（短語）作主語，若語義不一致，謂語用復數。

Toimprovepeople’slivesandtospeedupsocialconstruction

(be)

twoimportanttasks.動詞不定式（短語）作主語的主謂一致原則isisare不定式作主語基本用法：1.Tolookafterthesenaughtyboys_______(be)reallydifficult.2.Tosavemoneynow

_______(seem)impossible.

①

單一概念的動詞不定式作主語時，謂語動詞用單數形式。isseems3.TolearnEnglishwellandtomasteraskill

_______(be)veryimportantforyourfuture.4.Tojogeverymorningandtodosomestretchingexercisesintheevening

_______(be)goodwaystokeepfit.②

兩個及以上動詞不定式作主語，謂語動詞用復數形式。5.Toloveandtobeloved

______(be)thegreatesthappinessonecanget.areareis③

兩個并列的不定式語義基本一致，謂語動詞用單數形式。一、動詞不定式直接做主語優化P39[巧學活用1]——單句語法填空①________(finish)readingthebookwilltakeyoutwohours.②________(pay)avisittotheForbiddenCityismydream.③Toimprovepeople'slivesandtospeedupsocialistconstruction_____(be)twoimportanttaskstoday.④________(stay)uptoolateisabadhabitforourhealth.TofinishTopayareStaying2.動詞不定式與疑問詞who,whom,whose,what,which,when,where,how連用構成不定式短語做主語。Howtousethecomputeristhequestion.如何使用計算機是個問題。Wheretogohasnotbeendecided.去哪兒還沒有定下來。

注：疑問詞+不定式（to+do）（1）可用于該結構的疑問詞疑問代詞：who，whom，what，which

疑問副詞：when，where，how

（2）常接該結構的動詞：know，see，decide，tell，ask，consider，explain，learn，wonder（3）該結構的句法功能：主語、賓語和表語Howtoconstructthetheoreticalframeworkisveryimportant.Thequestioniswhentostartdevelopingsuchavaccine.Iknowwheretofindthatpatrioticyoungman.（3）該結構的句法功能：主語、賓語和表語Howtoconstructthetheoreticalframeworkisveryimportant.怎樣構建理論框架很重要。（作主語）Thequestioniswhentostartdevelopingsuchavaccine.問題是何時開始研制這種疫苗。（作表語）Iknowwheretofindthatpatrioticyoungman.我知道到哪里去找那個愛國的年輕人。（作賓語）【學法點撥】“疑問詞+不定式”結構相當于一個由疑問詞引導的名詞性從句。Ajudgemustdecidewhoseprooftobelieve.=Ajudgemustdecidewhoseproofhe/sheshouldbelieve.法官必須決定相信誰的證據。1._______________theriverisstillaproblem.（cross)怎樣過橋仍然是個問題。（作主語）2.______________________hasnotbeendecided.(gocamping)還沒有決定去哪兒露營。（作主語）3.Wehavenowidea__________________________________.我們不知道如何控制水污染。(control)（作賓語）4.Thequestionis________________________.(hold)問題是在那里舉行這個晚會。（作表語）

HowtocrossWheretogocampinghowtocontrolthewaterpollutionwheretoholdtheparty練一練補全下面句子[巧學活用3]——單句語法填空①How________(cure)thiskindofillnessisstillunknown.②Whether________(do)itornothasnotbeendecided.③How________(deal)withthiscasehasn'tbeenknownyet.tocuretodotodeal單句語法填空（1）Icouldn’tdecide

biketobuy.（2）Twentystudentswanttoattendtheclassthataimstoteachhow

（read）fast.（3）Whenandwhere

（vote）hasn’tbeendecided.完成句子（4）

（何時裝修）thehousehasn’tbeendecided.（5）Theydidn’tdecide

（在哪里舉行）thedebate.（6）Thequestionis

（怎樣拆卸）themachine.whichtoreadtovoteWhentodecoratewheretoholdhowtotakeapart 3.當主語較長，謂語較短時，常用it作形式主語放在句首，而將真正的主語—不定式放到謂語的后面。It’snoteasytoworkouttheproblem.=Toworkouttheproblemisnoteasy.計算出這道題不容易。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。為保持句子平衡，用it來作形式主語,相關句型有：（1）Itis/was＋形容詞＋(for/ofsb)＋動詞不定式若形容詞描述事物或行為的特征,用for,如difficult,possible,necessary等

若形容詞描述人的品格、特點,用of,如kind,polite,impolite,rude,foolish等（2）Itis＋a/an＋名詞(如apity/anhonour...)＋todo...（3）Ittakes

sb/sthtodosth

做某事花費某人多長時間/錢PresentationItisnecessaryforyoutochangeyourjob.It’sdifficultforustolearnEnglishwell.Itwassillyofyoutogiveupsuchagoodchance!It’sverykindofyoutosayso.若adj.“描述人的品格、特點”,用of,如kind,?nice,?wise,?silly,?polite,?impolite,?friendly,?foolish,?clever;若adj.“描述事物或行為的特征”,用for,如easy,?hard,?difficult,?possible,?important,?impossible,?necessary,good,?

bad,?exciting,?interesting,?surprising常用句型1：Itis+adj.+for/ofsb+todosthItisnecessary______youngstudentstolearna?foreignlanguage.Itwassilly______youtogiveupsuchagoodchance!

Itisimportant_______ustoexpressouropinions.Itwasnotpolite______youtodisturb

yourneighbourswithloudmusiclastnight.forofofPracticefor練一練1.Sometimesit’sbetter

（stay)calmwhenintrouble.2.Itwasfoolish

hertomakesuchamistake.3.

Itisrude

himtosaythattoalady.4.Itisdifficult

teenagerstolivealoneinaforeigncountry.tostayofofforPresentation常見的名詞有：pity,?shame,?pleasure,?one’sduty,?one’sjob,?fun,?joy,?goodmanners,?badmanners等Summary

常用句型2：Itis+n.+(forsb.)todosth.Itisanhonourtogiveaspeechinbehalfofmyschool.Itisapitytomissthechancetoseeyourshow.

Itisourdutytodothat.PresentationIttookmemorethananhourtodomyhomeworkyesterdayevening.Itwilltakeusalotofmoneytobuythathouse.Summary

常用句型3：Ittakes/took/willtakesb.sometime/moneytodosth.做某事花費某人多長時間(錢)[巧學活用]——單句語法填空①[2022·新高考卷Ⅰ應用文]Itismypleasure________(invite)youtoourEnglishshow“TalkandTalk”whichwillbeconductedat6a．m.thisFriday.②Itisgoodmannersfortheyoung________(give)theirseatstotheold.③Itismyambition________(make)surethatthedisabledpeoplehaveaccesstoallpublicbuildings.④Itisnouse________(argue)withhim,forheissostubborn.toinvitetogivetomakearguing4.動詞不定式與動名詞作主語時的區別：表示一般的、泛指的或習慣性的行為用動名詞；

表示具體的、一次性的或將來的動作用不定式。Swimmingisfuninsummer.夏天游泳是有趣的事。Toswiminthisriverisagreatpleasure.在這條河里游泳是件非常快樂的事。注意：有時這種區別并不很嚴格。但要注意：主語和表語要用同一種形式；平行結構中要用同一種形式。Toseeistobelieve.＝Seeingisbelieving.眼見為實。Presentation

Tolookafterchildrenisherjobtoday.她今天的工作是看孩子。Lookingafterchildrenisherwork.她的工作是照顧孩子。Comparethetwosentencesbelowandtellthedifferenceinmeaning.Summary不定式作主語和動詞-ing形式作主語的區別：

5.動名詞作主語表示_______________的行為;不定式作主語表示_________________________

動作。經常性或習慣性具體的、一次性的或將來的1.______(do)morningexercisesregularlyisgoodforyourhealth.

2.Itfeelsreallygood______(do)morningexercisestoday.Doingtodo_________(climb)mountainsisinteresting. _________(drive)acarduringtherushhourmustbetiring._________(teach)Englishismyjob. _________(teach)youEnglishthistermismyjob.No_________(smoke)ispermittedhere.

ltisnotverygoodforyou_________somuch(smoke)._________(read)moreisnecessary.

ltisquitenecessary_________(read)itagain.ClimbingTodriveTeachingToteachsmokingtosmokeReadingtoreadPracticemakesperfect1.______(do)morningexercisesregularlyisgoodforyourhealth.

2.Itfeelsreallygood______(do)morningexercisestoday.3.__________(finish)thetaskintimeisagreatchallenge.4.___________(walk)afterdinnerisgoodtohealth.5._________(get)totheparkbybikewilltakeabout20minutes.DoingtodopracticeTofinishWalkingToget5.不定式短語作獨立成分

tobegin/startwith首先

tosumup總而言之

toconclude總而言之

totellthetruth說實話

tobefrank坦白地說

tobehonest說老實話tobebrief簡言之

一些不定式短語可用作獨立成分，通常位于句首，有時位于句中或句末，要用逗號同其他句子成分隔開。Totellthetruth，Idon’tlikethegiftedactressinthemovie.說實話，我不喜歡這部影片中的那個有天賦的女演員。5不定式短語作獨立成分（1）一些不定式短語可用作獨立成分，通常位于句首，有時位于句中或句末，要用逗號同其他句子成分隔開。Totellthetruth，Idon’tlikethegiftedactressinthemovie.說實話，我不喜歡這部影片中的那個有天賦的女演員。（2）常用短語tosumup總而言之 tobebrief簡言之totellthetruth說實話 tobeexact確切地說 toconclude總而言之，最后 tobefrank坦白地說tobegin/startwith首先 tobehonest說老實話Tobefrank，yourtheoryistooabstractforthestudentstounderstand.坦白說，你的理論太抽象，學生們理解不了。 Practice（1）

（總而言之），mostofthecommitteememberssupportedtheideabutafewwereagainstit.（2）

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

（確切地說），tennovelsinherlifetime. （4）

（首先），he’stooyoungforthatkindofjob.（5）

（說老實話），Idon’treallywanttogotothepartytonight.Tosumup/ToconcludeTobebrieftobeexactTobegin/startwithTobehonesttodotodo作主語位于句首，在謂語之前todo作主語位于謂語之后，It作形式主語疑問詞+todo構成不定式短語，作主語和-ing作主語的區別Toreadwithoutreflectingislikeeatingwithoutdigesting.

Ittakessb.time/moneytodosth.Itis+adj.+（for/ofsb.）todosth.Itis+n.+(forsb.)todosth.todo表示具體的，將來的，一次性的動作-ing表示經常性、習慣性、抽象的動作與疑問詞who,whom,whose,what,which,when,where,how等連用Summarytodo作主語todo作主語位于句首it作形式主語疑問詞+todo構成不定式短語和-ing作主語的區別Toreadwithoutreflectingislikeeatingwithoutdigesting.Ittakessb.time/moneytodosth.Itis+adj.+(for/ofsb.)todosth.Itis+n.+(forsb.)todosth.todo表示具體的，一次性的、將來的動作-ing表示一般的，泛指的、習慣性的動作與疑問詞who,whom,whose,what,which,when,where,how等連用

SummarySummary1.todo作主語，表具體的特指未完成動作,謂語用單數（doing作主語常表習慣性動作）Tochangebadhabitsisnevereasy.2.it作形式主語常見于以下情況中(真正的主語—不定式)。1)Itis+adj.+for（表事物特征）/of（表品質）sb.todosth.表品德的adj:kind,?nice,?wise,?silly等

表事物特征的adj:easy,?hard,?difficult,?possible2(Itis+n.+(forsb.)todosth.常見的名詞有：pity,?shame,?pleasure3)Ittakes/took/willtakesb.sometime/moneytodosth.3.疑問詞who,whom,whose,what,which,when,

where,how+todo，也可作主語。Part3Practice1.Itisveryhelpfulforallofus________(help)agoodknowledgeofhistory.2.It’snecessaryforyou________(lock)thecarwhenyoudonotuseit.3.Afraidof___________(bite)bysnakes,theboywasafraid________(touch)them.4.________(get)therebybikewilltakeushalfanhour.PraticetohelptolockbeingbittentotouchToget單句語法填空（1）Sometimesit’sbetter

（remain）silent.（2）Although

isahardtasktoprotectourenvironment，wecan’thelpbutgoahead.

（3）

（control）theairpollutionisnecessary.（4）Itwasfoolish

himtoendangerhislifeinthatway.（5）Don’tyouthinkitisrude

himtoaskaladyherage?（6）Itisdifficult

himtoliveonsuchasmallsalary.

toremainitTocontrol/Controllingofoffor1.Ittookusabouttwohours

(get)therethatday.2.Whether

(hold)apartythisweekendhasn’tbeenknownyet.3.Itisfoolish

youtotakeataxitothetowninthatsituation.4.Itisimportantforher

(prepare)fortheexamination.5.It’sourduty

(keep)ourenvironmentcleanandtidy.6.Itisnogoodforyou

(wait)hereforalongtime.7.

(get)therebybikewilltakeushalfanhour.togettoholdoftopreparetokeeptowaitTogetExercisesPleasefillintheblankswiththerightformofthewordsgiveninthebrackets.1.Itisreallyhardforaforeigner__________(pick)upChineseinsuchashorttime.2.It’sreallykindofyou________(help)mewithmymath.3.________(travel)totheMeiliSnow-cappedMountainMr.Jones’sdreamofthisyear.topicktohelpTotravel練一練4.Ithinkitnecessary_____________(practice)listeningandspeakingEnglisheveryday.5.Itcantakesometime___________(recover)fromtheCovid-19infection.6.InKunming,_________(miss)abusmeanswaitingfor15minutes.topracticetorecovermissing練一練

1．

(lean)outofthewindowisdangerous.2．

(save)moneynowseemsimpossible.3．Itisanoffence

(drop)litterinthestreet.4．Itisstupidofyou

(write)downeverything(that)theteachersays.5．__________(say)isonethingandtodoisanother.6．Itseemedapity__________________(waste)somuchtime.7.Idon’tthink__________________________（你問……是不禮貌的）howlongtheinterviewwilllast.8.

（保衛……是我們的職責）thecountryagainstitsenemies.9.

（……花了我半個小時）towashtheclothes.Tolean

Tosave

todropActivity7

Completethesentencesusingthecorrectformsofthewords.

towrite

Tosay

tohavewasted

itisimpoliteofyoutoask

It’sourdutytodefend

Ittookmehalfanhour

10.Ilikeeatingfriedtomatoeswitheggs,andIthoughtitmustbeeasy________(cook).11.Itiseasyforthem__________(care)

for.

12.Itwassogood_______(feel)acceptedforwhatI’mgoodat.13.It’smyfirsttime_______(hear)ChinesestoriestoldbyanEnglishspeaker.14.Thenwewillknowhowimportant______istohavemeaninginourlife.15.Itisnotasimplematter____________(determine)thenatureoftalent.16.___________(learn)tothinkcriticallyisanimportantskilltoday’schildrenwillneedforthefuture.17.Onourwaytothehouse,itwasrainingsohardthatwecouldn’thelpwonderinghowlongitwouldtake_______(get)there.tocooktobecaredtofeel

tohearittodetermineLearningtogetYoudon’tneedtobetoldthatitisdifficult1.______(lose)weight.Or,2._______(keep)theweightoffonceyouhavedroppedthosepounds.Now,itistimeforyou3.___________(identify)thefactorsthatcauseyouroverweight.Forinstance,youmaydiscoverthatyouspendtoomuchtime4._________(be)inactive.Or,thatyoutendtoskipmealsandsnackinstead.Onceyou5._____________(figure)outtheproblem,youwillfindyourselfonestepclosertocorrectingyourissues.6.________(eat)healthyfoods,gettingenoughsleep,andexercisingregularlycanalsotheanswer.So,itisimportant7._________(make)anefforttoleadahealthylifestylewhenyouaregoingthroughatoughperiod.Theseareallthewaysyoucanchangeyourlifestylesothatyouwillfinditeasier8._________(slim)down.What’smore,byadoptingthesehealthytips,youwillnoticethatyouhaveaneasiertime9._______(keep)theweightoffaswell.So,makeitapoint10.___________(follow)theguidelinesmentionedabove.Fillintheblanksusingtherightformsofthegivenwords.tolosetokeeptoidentifybeinghavefiguredEatingtomaketoslimtokeeptofollow語法填空Mikedrovetoaremotebordertownalone.Hedidn’tstopthecar1.________(take)abreakalthoughhewasfeelingtired.Asaresult,atrafficaccidentoccurred,whichcausedhim2.______

__(trap)insidethecar.Fortunatelyagirlwhohappenedtopassbyvolunteered3.________(save)him,only4.________(find)Mikewascompletelylockedinthecar.Aftercallinganambulance,shemanaged5.________(give)himfirstaid,usingthemethodshehadlearnedatschool.Soon,Mikewasrushedtohospitalinanambulance.Ittookhimthreemonths6._______

_(recover)fromhisinjuries.ThegirlnamedMaryfeltpleased7._

_______(do)suchagreatthing,thoughsherealizedthecarmayhaveexploded.Wheninterviewed,shesaid,“I’vealsometwithatrafficaccident.Akindpasser-bysavedmylifebuthewaskilled.Iwastheonlyone8._______

_(survive)thecrash.Themanwassaid9._

_________________(work)ontheroadhelpingpeopleinneedfortenyears.Iwastoomovedeventospeakwhenhearingthestory.Therefore,Idetermined10.________(stay)hereandgivepeopleinneedahelpinghand.”tostaytotaketobetrappedtosavetofindtogivetorecovertohavedonetohavesurvivedtohaveworkedHomework2.Jointhewordstomakefullsentences.1.important/avoid

/passivecigarettesmokingItisimportanttoavoidpassivecigarettesmoking.2.willtake/nutritionspecialist/abalanceddietmenu/make/anhour/

foryou____________________________________________________________3.useful/turnto/fitnessconsultant/foradvice____________________________________________________________4.illegal/dangerous/take/drugs_______________________