人教版高中英语必修五动词不定式

英语语法（动词不定式）定义：动词不定式是一种非限制动词形式，即非谓语动词。非限定动词是指不能单独在句中充当谓语的动词形式。非谓语动词包括：动词不定式，-ing分词和-ed分词。动词不定式在语法功能上可作主语、宾语、表语、定语和状语。2.不定式的用法1）不定式结构作主语.Toseeistobelieve..Tofinishthattaskinsuchashorttimeisreallyachallenge.在上述情况下，如果不定式较长，显得头重脚轻，则可由it作形式主语，而将不定式放到后面。如：Itisreallyachallengetofinishthattaskinsuchashorttime.It's...forsbtodo.和It's...ofsbtodo.forsb.句型中的形容词一般为表示事物的特征特点，表示客观形式的形容词，如easy,hard,difficult,interesting,impossible等：例如：It'sveryhardforhimtostudytwolanguages.对他来说学两门外语是很难的。ofsb句型中的形容词一般为表示性格，品德，心智能力，表示主观感情或态度的形容词，如careless,clever,considerate,foolish,good,impolite,kind,naughty,nice,silly,stupid。例如:It'sveryniceofyoutohelpme.你来帮助我，你真是太好了。2）不定式作宾语不定式作宾语有两种：一种是及物动词后直接跟带to的不定式，另一种是“及物动词+疑问词+带to的不定式。及物动词+带to的不定式结构：只能跟动词不定式的动词，常见的有:afford,agree,aim,appear,ask,decide,demand,desire,determine,expect,fail,happen,hesitate,hope,intend,learn,long,manage,offer,pretend,promise,prepare,refuse,seek,swear,want,wish等。.Hemanagedtosolvethecomplicatedproblem..Thestrangerofferedtoshowmetheway.动词+疑问代（副）词+不定式：这类动词常见的有advise,decide,findout,forget,inquire,know,learn,see,remember,teach,tell,understand,wonder等。常见的疑问代（副）词有:what,when,where,which,how,whether等。.Hedoesnotknowwhentostart..Youcandecidewhethertocontinueortostop..Iwillshowyouhowtodealwithit.有时，不定式可由it代替，而把不定式放到后面去。这可以用这一结构表达：动词（如find,think,consider,feel等）+it+形容词+不定式。.Sheconsidersitnecessarytomakefriendswithhim.2.Wefinditdifficulttofinishallthehomeworkbefore9o,clock.3）不定式做表语不定式可放在be动词后面，形成表语。例如：1.Toseeistobelieve.另一种情况为主语是以aim,duty,hope,idea,job,plan,problem,purpose,thing,wish等名词为中心的短语，或以what引导的名词性从句，不定式表语对主语起补充说明作用：；例如：.Hisaimistostudyabroadinthenearfuture..Themostimportantthingistonegotiatewiththemabouttheprice..WhatIwanttosayistoforgetalltheunhappyexperience.4）不定式作定语第一种，被修饰的名词词组是不定式的逻辑宾语。例如：.Therewasreallynothingtofear..Hegavemeaninterestingbooktoread.如果不定式是不及物动词，后面就得加相应的介词。例如：.Maryneedsafriendtoplaywith..Thatgirlhasnothingtoworryabout..Althoughthefilmhadbeenonfortenminutes,Istillwasnotabletofindachairtositon.第二种，被修饰的名词词组是不定式的逻辑主语；例如：.Haveyougotakeytounlockthedoor?.Theactiontobetakeniscorrect.5）不定式作状语1）目的状语常用结构为todo,inordertodo,soastodo,so（such）...asto…（如此…以便…）。例如：Heransofastastocatchthefirstbus.他飞快地跑以便赶上第一班车。Icomeheretosaygood-byetoyou.我来是向你告别。2）作结果状语，可以表示没有预料到的或事与愿违的结果，不定式要放在句子后面。Iawoketofindmytruckgone.我醒来发现箱子不见了。Hesearchedtheroomonlytofindnothing.他搜索了房间，没发现什么。3）表原因I'mgladtoseeyou.见到你很高兴。Shewepttoseethesight.她一看到这情形就哭了。4）表示理由和条件Hemustbeafooltosayso.Youwilldowelltospeakmorecarefully.不带to的不定式的使用动词不定式通常带to,但在有些搭配中不带to,在另一些搭配中可带to可不带to。归纳起来，以下情况下使用不带to不定式：在can/could,may/might,will/would,shall/should,must,need,dare等情态动词之后，动词不定式不带to。2）在感官动词，如see,feel,watch,notice,smell,hear,observe等后，或使役动词，如have,let,make等后，动词不定式不带to。例如:oftenheardhimsaythathewouldstudyhard.2.Imusthavehimseehisownmistakes.但是，当这类结构转换为被动语态时，后面的不带to不定式一般转换为带to不定式。例如：1.Hewasoftenheardtosaythathewouldstudyhard.3）在动词help之后可用不带to的不定式，也可用带to的不定式。例如：1.Helptheoldlady（to）carrytheheavybox.4）在hadbetter,wouldrather,may/mightaswell最好还是，不妨，ratherthan,cannotbut不得不，等搭配之后，动词不定式也不带to。例如：1.Unlessyoufeeltoilltogoout,Iwouldrathernotstayathometonight.2.Shecouldnotbutcriticizehisfoolishbehaviour.5）在介词but,except之后，如果其前有动词do的某种形式，其后不定式一般不带to,反之则必须带to,表示“不得不，只能”。例如：.Hewilldoanythingexceptworkonthefarm..Therewasnothingleftfortheenemytodobutsurrender..Ihadnochoicebuttowaittillitstoppedraining.6）紧跟在why或whynot之后的动词不定式总是不带to。但是，紧跟在who,what,which,whether等连接词后的不定式带to。例如：Whystandupifyoucansitdown?Whynotaskyourteacherwhenyoudon'tunderstandthemeaning?Youneedn'tdecideyetwhethertostudyartsorscience.4.不定式的时态语态：（以todo为例）时态主动被动一般式TodoTobedone完成式TohavedoneTohavebeendone进行式Tobedoing完成进行式Tohavebeendoing1.Shefeelsrelaxedtohavefinishedwritingherthesisbeforethedeadline..TheVikingsarebelievedtohavediscoveredAmerica.Whenyoucalledmelastnight,Ihappenedtobeworkingonthecomputer..Thesnowwassupposedtohavebeenblownoffthemountain.不定式的否定形式否定形式是在不定式的标志to前加not。例如：1.Idecidednottoaskhimagain.2.Pleaseremembernottoleavethelightsonwhenyouareout.I.单项选择：Heseemstheoldlady.A.knowingB.tobeknowingC.toknowD.tobeknownTom_whentheyspokeillofhim.A.happenedtobepassedB.happenedtobepassingbyC.happenedpassingbyD.happenedtopassedWeallhope_scientists.A.becomeB.tobecomeC.becomingD.becameTheboyrefusedforclimbingthetalltree.A.topayB.tobepaidC.beingpaidD.payingIhappenedthearticlewhenheaskedmeaboutit.A.havingreadB.tohavereadC.tobereadD.readingwithhimisagreatpleasure.A.TotalkB.TalkC.TalkedD.TotalkingItisniceyourvoice.A.tohearB.hearC.heardD.tobehearing8.istostruggle. A.LivingB.LiveC.ToliveD.TobelivedHerwishisadoctor.A.becomingB.becomeC.tobecomeD.beingcomeIwasjustabouttheofficewhenthephonerang.A.leavingB.leaveC.toleaveD.toleavingIdidn,tituntilyouhadexplainedhow.A.managetodoB.managedtodoC.managetohavedoneD.managedoing12.Hefounditimportantthesituationallovertheworld.A.studyB.tostudyC.studiesD.tobestudiedAtlasttheenemysoldiershadnochoicebuttheirguns.A.tolaydown B.liedown C.layingdown