Unit1Grammarandusage（动词不定式作主语和表语）课件-高中英语牛津译林版（2020）选择性必修第一册

Non-finiteverbGRAMMARAREVIEW动词不定式一般由“to+动词原形”构成，其否定形式是“nottodo”。动词不定式可以带宾语或状语构成动词不定式短语，没有人称和数的变化，但有时态和语态的变化。动词不定式不能单独作谓语，可以作主语、宾语、表语、定语、补语等。如：Tofinishthetaskinaweekisveryhard.Thebigboymanagedtopasstheexam.Myworkistocleanthegardeneveryday.ShewasthefirstwomantoswimacrosstheEnglishChannel.Tellhimtocomeherethedayaftertomorrow.主宾表定补Asarealfoodie,Ienjoyallkindsoffoods.Mydreamistotrydifferentrestaurantsandtastevariousfoods.YesterdayIinvitedsomefriendstotryagreatnewrestaurantfordinner.Nothingcanstopourdeterminationtohaveatry.Wedecidedtowaitoutside.Afteranhourofwaiting,wewereinvitedtogointotherestaurantandtaketheorder.Thedishesareextremelydelicious.Itisworthwhiletohavesuchalongwait.Lead-inFindoutto-infinitivesandguesstheirfunctions.表宾主补补01usedassubject1.动词不定式作主语，表示具体的、一次性的或者表示将来含义的动作，且谓语动词常用单数。如：

Tomasteranewskillisnotaneasything.

Toseeistobelieve.

Tohelpothersisourduty.Totalkwithherisagreatpleasure.

01usedassubject

2.动词不定式短语作主语时，为了保持句子平衡，往往用it作形式主语，而将动词不定式短语置于句末。如：

ItisimportanttoenlargeEnglishvocabulary.ItwouldbeawasteoftimetolookupeverynewwordwhenyoureadanEnglishnovel.

其常见句型有以下4种：①

It＋is＋名词＋todosthIt'sourdutytotakegoodcareoftheold.②

Ittakes/tookwilltakesb＋sometime/money＋todosthItwilltakeusthreehourstowalkthere.③

It＋be＋形容词＋for/ofsb＋todosthIt’sverykindofyoutotelluswhathappenedyesterday.Itisimportantforchildrentotellrightfromwrongatanearlyage.④Itseems(appears)＋形容词＋todosthItseemedimpossibletofinishtheworkontime.01usedassubject

用it做形式主语改写下面句子(1)TospeakEnglishwellisn'taneasyjob.

(2)Toimproveourteachingmethodisveryimportant.

(3)Totalkwithherisagreatpleasure.

(4)Tolookupeverynewwordwouldbeawasteoftime.

Itisn’taneasyjobtospeakEnglish.

Itisveryimportanttoimproveourteachingmethod.

Itisagreatpleasuretotalkwithher.

Itwouldbeawasteoftimetolookupeverynewword.01usedassubject

3.“特殊疑问词+不定式”构成的不定式短语作主语时，且谓语动词常用单数。常见的特殊疑问词有：what,who,which,when,where,why,how等。如：

Wheretoholdthemeetinghasn’tbeendecided.

Howtorelievethepainisaquestion.02usedaspredicative

1.动词不定式作表语，通常说明主语的具体内容。

其主语通常是aim,ambition,dream,duty,goal,idea,intension,plan,purpose,task,way,wish等表示意向、打算、计划的词。如：Hisambitionistobecomeanactor.Herdutyistolookafterthechildren.

不定式作表语通常可以和主语位置互换。Mydreamistobeadoctor.＝Tobeadoctorismydream.02usedaspredicative

2.某些系动词，如be（是）、seem（看起来）、appear（看起来）、prove（证明）、turnout（结果）等，后面可以接不定式作表语。其中，除了be动词之外，seem、appear、prove、turnout后面的表语若是以“tobe+...”的形式出现，通常可以省略tobe。He

seems(tobe)busy.

＝He

appears(tobe)busy.Theplan

proves(tobe)right.

＝Theplan

turnsout(tobe)right.

Attention:

有些系动词，如sound（听起来）、smell（闻起来）、taste（尝起来）、feel（感觉）、become（成为）等，通常不可以接不定式作表语。练习：判断下列句子正误Itsmellstobedelicious.Thebookseemsavailable.Thecaketastestobeyummy.

F

T

F02usedaspredicative3.“特殊疑问词+不定式”通常与be动词构成系表结构，作be动词的表语。如：Thequestionishowtocarryouttheplan.4.当主语部分有实义动词

do

时(以及do的其他形式时),作表语的动词不定式通常要省略to

(即“前有do,后无to”)。如：Whatyoushoulddois(to)openthedoor.AllIwanttodonowis(to)havearest.

单个不定式(不定式短语)做主语，谓语动词用单数Toplaybasketball______(be)great.如果and连接两个或更多并列的不定式(不定式短语)作主语，谓语动词就用复数Toimprovepeople’slifeandtospeedupsocialistconstruction______(be)ourtwoimportanttasks.Whenandwheretodo________________________(notdecide)yet.Whattodoandwheretodo___________________________(notdecide)yet.isarehasn’tbeendecidedhaven’tbeendecided1.It’sbadforyoureyes________(play)computergamestoomuch.2.Hisambitionis_____________(become)asuccessfulscientistwhenhegraduates.3.___________(enjoy)theconvenienceofdigitalpayment,manyseniorcitizensstartedtousesmartphones.4.Whatwecandois____________(ensure)thatallstudentshaveaccesstoahealthydiet.5.It’sreallykindofhim________(let)ususehisswimmingpool.toplaytobecomeToenjoy(to)ensuretoletPracticeBApplyingtherulesDearTom,IamwritingtothankyoufortakingmetoSkyBuffet.Itwassokindofyoutoinvitemeandbookatablebythewindow.Itwaswonderfultoseethecitysceneryandwatchthebeautifulsunset.IhavealwayswantedtogiveSkyBuffetatry,andit