高考英語二輪復習不定式做主語課件25張

選擇性必修三Unit2todousedasSubjec1.Studentscanunderstandthemeaningandfunctionoftodousedassubject;2.Studentscanmasterthesentencestructureofitastheformalsubject,andtodoisthetruesubject;3.Studentscantellthedifferencebetweentodousedassubjectanddoingusedassubject;3.Studentscanapplywhattheyhavelearnedintopractice;Teachingobjectives

1._______(prevent)harmfulhabitslikethesefromdominatingateenager'slifeisessential.2.________(change)badhabitsisnevereasy,evenwithmanyattempts.3.Afterall,itisnoteasy_______(break)badhabits.4.However,duringthisperiod,itcanbeeasyforsomeofthem_______(form)badhabits.Readthefollowingsentences

1.Topreventharmfulhabitslikethesefromdominatingateenager'slifeisessential.2.Tochangebadhabitsisnevereasy,evenwithmanyattempts.3.Afterall,itisnoteasytobreakbadhabits.4.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.

todo作主語與it作形式主語之間的轉換

Itwilltakethenutritionspecialistanhourtomakeabalanceddietmenu

foryou.Itisusefultoturntothefitnessconsultantforadvice.Itisillegalanddangeroustotakedrugs.Itisoftenharmfultoskipbreakfast.不定式作主語，有時根據(jù)表達的需要，可以在添加疑問代詞或副詞，疑問代詞：who，whom，what，which疑問副詞：when，where，howwhetherE.g.Howtobreakthebadhabitisthequestion.Wheretogohasn'tbeendiscussed.IthasnotbeendecidedwhethertoflytoParis.

”疑問詞+todo”作主語

總結

思考

位置

含義

本質

名詞詞性

不定式短語在句中做主語。doingtodo(somethingyouhavealreadydone)Doing...ismyfavoriteactivityDoing...oftenhelpsme...(somethingyouwanttodo)Todo...isessentialforus.Todo...canhelpme...eatfruitsandvegetablesdrink8glassesofwateradaywashhandsbeforemealshaveenoughsleepwalkaftermealstakeregularexercise一【含義】

一般表示具體的或某一次的或將來的動作。二【位置】

1.Topreventharmfulhabitslikethesefromdominatingateenager'slifeisessential.2.Tochangebadhabitsisnevereasy,evenwithmanyattempts.3.Afterall,itisnoteasytobreakbadhabits.4.However,duringthisperiod,itcanbeeasyforsomeofthemtoformbadhabits.

句首it作形式主語,不定式放句尾考點一：不定式作主語時的主謂一致原則

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(shù)單數(shù)復數(shù)ToimproveEnglish_____themosturgentthingformenow.Toloveandtobeloved_____________issweettous.Tobuildupourphysicalandmentalhealthandstimulateourinterestinlearning_______(be)twoessentialtasks.

Exercises考點二：it作形式主語常見的句型1.Itis+形容詞+for/ofsb+todosthE.g.Itiseasyformetolearnhowtodrive.Itiscleverof

youtoapplyfortheposition.

總結一般規(guī)律：若形容詞”描述人的屬性，特征”,用of;若形容詞“描述事或物的特征”,

用for;

Exercises2.Itis+名詞(apleasure/apity/anhonour...)(forsb)+todosthE.g.Itisanhonourtogiveaspeechinbehalfofmyschool.Itisapitytomissthechancetoseeyourshow.3.It

takes/took/willtakesb.sometime/moneytodo

做某事花費,某人多長時間(錢)E.g.Ittookmemorethananhourtodomyhomeworkyesterdayevening.拓展1：it作形式主語,doing作真正的主語1.浪費時間做某事:Itisawasteoftimedoingsth2.做某事是沒有用的It'snouse/nogooddoingsthIt'suselessdoingsthItisfun/nofundoingsth拓展2：todo和doing作主語的區(qū)別Tolookafterchildrenisherjobtoday.

她今天的工作是看孩子。Lookingafterchildrenisherwork.

她的工作是照顧孩子。區(qū)別todo通常表示一個將來的、具體的內容;

(動作)doing而則表示一種經常性的、習慣的或抽象的概念。(事情)todo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(qū)別Toreadwithoutreflectingislikeeatingwithoutdigesting.Ittakessb.time/moneytodosth.Itis+adj.+(for/ofsb.)todosth.Itis+n.+(forsb.)todosth.todo表示具體的，將來的動作-ing表示一般的，已經完成的動作與疑問詞who,whom,whose,what,which,when,where,how等連用

Summary

總結1.Itis+adj.+(forsb)todoItiseasyformetolearnhowtodrive.2.Itis+adj.+(ofsb)todoItiscleverofyoutoapplyfortheposition.Mattersnee