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

語法精講Unit2

TheInfinitive

(todo……)不定式的時態(tài)和語態(tài)不定式主動被動

一般towritetobewritten

進行tobewriting

完成tohavewrittentohavebeenwritten

完成進行tohavebeenwriting

4.Itisimportant

______Tomtogetthatjob.Itiskind______youtohelpmewithmyhomework.

1.______(talk)withhimisagreatpleasure.2.______(help)othersisourduty.TotalkTohelpItisourdutytohelpothersforof3.Itiseasy______________________(學生讀)forthestudentstoread.Lookatthefollowingsentencesandpayattentiontotheitalicisedinfinitives.Findmoreinfinitivesinthereadingpassage.Inpairs,discusstheirmeaningsandfunctions.1Tochangebadhabitsisnevereasy.2Ittookthesurgeon(n.外科醫(yī)生)threehourstofinishmymother’slungsurgery(n.外科手術).主語主語3TojointhePeople’sLiberation(n.解放)Army,itisrequiredformentoshaveoff(剃掉,刮掉)theirbeards.4Itwasnotpolitetodisturb(v.打擾)yourneighbourswithloudmusiclastnight.目的狀語主語主語Moresentencesinthereadingpassage:1.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.2.Topreventharmfulhabitslikethesefromdominatingateenager’slifeisessential.3.Tochangebadhabitsisnevereasy,evenwithmanyattempts.4.Afterall,itisnoteasytobreakbadhabits.動詞不定式作主語常見的三種形式1.不定式作主語通常位于句首，表示具體的某次動作，謂語動詞用單數(shù)。e.g.Toseeistobelieve.百聞不如一見。Togetupearlyisnecessary.早起是必要的。Tolearnaskillisveryimportantforeveryoneinsociety.?學習一項技能對社會上的每個人都很重要。Tofinishthebuildinginamonthisdifficult.要在一個月內完成這座建筑是困難的。2.動詞不定式與疑問詞who,whom,whose,what,which,when,

where,how等連用構成不定式短語，也可作主語。

e.g.Howtousethecomputeristhequestion.如何使用計算機是個問題。Wheretogohasnotbeendecided.去哪兒還沒有定下來。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。e.g.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。it作形式主語代替真正主語不定式常見于以下情況中：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Itis+adj.+for/ofsb.todosth.e.g.Itisnecessaryforyoungstudentstolearna?foreignlanguage.對年輕的學生來說，學習一門外語是必要的。Itisnecessaryforyoutochangeyourjob.你有必要換工作。Itwasimpossibleforthemtocompletethetaskinsuchashorttime.他們不可能在這么短的時間內完成這項任務。It’simportantforustokeepthewaterclean.保持水質清潔對我們來說是很重要的。常見的此類形容詞有：

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

你放棄這么好的一個機會，真傻!It’sverykindofyoutosayso.你這樣說真是太好了。Itisfriendlyofthefamilytotrytomakemefeel

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

乘宇宙飛船飛往月球一定很有趣。Ittakes/took/willtake

sb.sometime/money

todosth.做某事花費某人多長時間(錢)e.g.Ittookmemorethananhourtodomyhomeworkyesterdayevening.昨天晚上我做作業(yè)用了一個多小時。Itwilltakeusalotofmoneytobuythathouse.買那套房子要花費我們很多錢。3.如果要說明不定式表示的動作是誰做的，可以在不定式前加一個由for/of引起的短語,構成__________。2.不定式作主語時,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.單個不定式作主語，謂語動詞_________單數(shù)形式主語不定式的復合結構語法總結(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4.illegal/dangerous/takedrugs5.harmful/skipbreakfast/oftenItisillegalanddangeroustotakedrugs.Itisharmfultoskipbreakfastoften.n.毒品，藥品v.跳過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