(infinitive)概说:动词不定式(todo)是学习英语课的一个重点。动词不定式属于非谓语动词的一种形式,很多同学经常把它和谓语动词混在一起,掌握起来有困难。下面我们对动词不定式的用法做简单归纳,帮助同学们记忆动词不定式的主要用法一、动词不定式在句子中不能独立充谓语,没有人称和数的变化。二、动词不定式是由“to+动词原形”构成(有时可以不带to)。动词不定式的否定形式是“not+动词不定式”(此时not不能再与助动词连用)。三、动词不定式短语具有名词、形容词和副词等功能,可在句中用做多种句子成分。主语宾语表语定语状语宾补作主语常置于句末,而用it代替其做形式主语。例:Togoinforsportshelpsyoustayfit.Ithelpsyoustayfittogoinforsports.Itisdangeroustoswiminthedeepseaonyourown.注:此句式中不定式逻辑上的主语可由for或of引出,逻辑主语由of引出时,表语的形容词为kind,nice,good,polite,clever,foolish,right,wrong等表示性格品质评价的形容词。例:It’srightofhimtorefusetheinvitation.(him为逻辑主语)点击规律:动词不定式在句中作主语时,除了直接作主语外,常放在:Itis+adj.(形容词)+todosth.或Itis+n.(名词)+todosth.句中,it仅作形式主语。作宾语此种情况可按固定搭配或句式去记。例:wouldyouliketoseemyphotos?Tomplannedtovisithisuncle.类似用法的词还有:start,want,agree,hope,begin,decideagree,love,like,hate,prefer等。Ifounditverydifficulttogetajob.(it为形式宾语)点击规律:这些动词后面除接不定式外,还可以接动名词,意思区别不大提示板:likedoing指经常性动作,而liketodo指一次性的动作。Ilikeswimming,butIdon‘tliketoswimnow.stop,forget,remember,goon,try等词或短语后面可以接不定式。点击规律:上述动词后面接不定式和接动名词意思大不相同。提示板:1)stoptodosth.:停止一件事,去做另一件事。stopdoingsth.:停止正在做的事。例句:Whentheteachercamein,thestudentsstoppedtalking;当老师走进来时,学生们停止说话;whenhecameout,thestudentsstoppedtotalk.当老师走出去时,学生们又开始说话。2)思考:forget,remember,goon,try等词或短语后面接不定式和动名词用法有何区别?点击规律:在find/feel+it+adj.+todosth.句型中,it是形式宾语,真正的宾语是后面的动词不定式。如:Themandownstairsfounditdifficulttogettosleep.Ifeeliteasytorecitethetext.点击规律:某些动词或短语后面既可以接动词不定式作宾语,又可接动名词作宾语,二者用法上的区别可以通过造句子加以区分,如上页的stop例句。作表语放在连系动词be后作表语例句:Hiswishistobecomeascientist.Ourdutyistoprotecttheenvironment.Thefirstimportantthingistosavethesoldiers’lives.当务之急是抢救战士们的生命。点击规律:动词不定式在句中作表语时,通常对连系动词前面的名词进行诠释说明。作定语动词不定式做定语放在所修饰的名词、代词的后面。例:1)Heisthefirstpersontosailaroundtheworld.2)Ihavealotofworktodo.3)Thedoctorsaidhecoulddonothingtohelptheboy.点击规律:动词不定式若在句中作定语,常放在被修饰的名词、代词之后。提示板:如果动词不定式和前面所修饰的词构成动宾关系,且动词是不及物动词,切记不要忘掉后面的介词。如:1)Ihaveasmallbedroomtolivein.2)Haveyougotsomepenstowritewith?作状语a.目的状语:放在go,come,use,live,inorder等词后面。如:1)Icometoseeyou.2)Herunsfastinordertogetthereintime.3)Theybroughtinphotosoftheirfamiliesformetolookat.b.原因状语:放在sorry,glad,surprised,disappointed,excited等词后面。(有些资料上把这类称为不定式在表示心理、情感、评价等的形容词后,对其进行补充说明,作形容词补足语)如:1)Iamgladtoseeyouhere.2)Iamsorrytotroubleyou.c.作结果状语。如:1)Someoftheapplesarehardtoreach.2)Theroomislargeenoughtohold1000people.作宾语补足语(1)在多数复合宾语及物动词后要带to:tell,ask,want,order,teach,invite,warn,wish,help,get,wish,等词后面常接不定式作宾补。例:1)Iaskedafriendtoreadittome.2)Itellhimnottogotherebybus.3)Edison‘smothertaughthimtoreadandwrite.(2)在表示感觉、致使等意义的动词(see,watch,hear,feel,make,let,have,observe,notice,help等)后不带to的不定式作宾补。如:1)Thebossmakesthemwork16hoursaday.2)Iheardhersinginthenextroom.提示板:若变成被动语态,在上述结构中,不定式符号to要加上。如:1)Theyaremadetowork16hoursadaybytheboss.2)Shewasheardtosinginthenextroom.疑问词+不定式用法不定式前可带what,who,which,where,when,how,whose,等疑问词,这种不定式短语在句中作宾语、宾语补足语、主语等。例:此外,还涉及到“不定式被动语态一般式(tobe+过去分词)”例:Therearetwentymoretreestobeplanted.(直宾)(宾语)(宾语)(宾语补足语)(主语)1)Hedidn’ttellmewheretogo.2)Idon’tknowwhattosaynow.3)Idon'tknowwhattodonext.4)Hetaughtushowtousethecomputer.5)It'sstillaquestionhowtogetthere.根据句意,用括号内所给动词的适当形式填空。1.It'stimeforus(have)supper.2.Wouldyoulike(go)shoppingwithme?3.Ittookushalfanhour(work)outtheproblem.4.Heisoldenough(join)thearmy.5.Ifeelstrange(have)atwinsister.6.Iamveryglad(meet)youhere.7.Theyprefer_____(stay)athomeratherthangoout.8.Wesawthem(come)intotheroomjustnow.9.Whathesaidmademe_____(feel)sorry.10.Iamsorry.Iforgot_____(tell)youthenews.tohave主语togo宾语towork主语tojoin结果状语tohave形容词补足语tomeet形容词补足语tostay宾语tocome宾补tofeel宾补totell宾语11.Hisplanis(spend)afewdaysinthemountains.12.Haveyougotanything_________(say)?13.Haveyoudecidedwhichone_________(choose)?14.Doyouknowwhen_________(start)?15.Heistooweak________(carry)thebigstone.tospend定语tosay定语tochoose表语tostart不定式短语作宾语tocarry结果状语Hi,relaxyourself!