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1、动词不定式的基本用法归纳一、动词不定时的形式:肯定式:todosth否定式:nottodosth.被动式:tobedone一般被动否定式:nottobedone完成主动式:tohavedone完成否定式:nottohavedone完成被动式:tohavebeendone完成被动否定式:nottohavebeendone动词不定式的基本用法归纳二、动词不定式的用法1.作主语A动词不定式作主语,谓语动词用单数形式。如:Toseeistobelieve.(Seeingisbelieving.)Mychiefpurp
2、oseistopointoutthedifficultiesofthematter.Herwishistobecomeadoctor.B不定式或不定式短语作主语时,常用it作形式主语,构成“Itis+形容词(+forsb.)不定式”结构。Itisimpossibleforhimtogiveupsmoking.2.作宾语A.动词后直接不定式作宾语的动词有许多,如want,decide,intend,fail,wish,export,pretend,choose等等。Imeantogothereatonce.B.
3、不定式短语作宾语时,如果还带有宾语补足语,往往把不定式短语放在宾补之后,而用it作形式宾语。句型为“主语+find(feel,think,believe,consider,etc)+it+形容词/名词+todosth”。Ithinkitnecessarytoreportthethingtotheteacher.Ifinditinterestingtoworkwithhim.C.动词不定式还可以用作介词宾语,但仅限于介词except和but(除了)。常用句型有:Thereisnothingtodobut+动词原
4、形donothingbut+动词(除做….之外别无选择)canbut+动词原形(只能原形(“只有做……)havenochoicebuttodo,只得)cannothelp/choosebut+动词原形(不能不……)but+不定式的用法①不定式在介词but,except,besides,otherthan后面时,如果这些介词之前有行为动词do(非助动词)的各种形式时,那么这些介词后面的不定式不带to,否定带to。e.g.Shecoulddonothingbutcry.Whatdoyouliketodobesid
5、esswim?Ihavenochoicebuttowait.Therewasnothingformetodootherthanwaituntilthemeetingwasover.IhadnothingtodobutwatchTV.②当句子的谓语动词是can’t,can’thelp,can’tchoose等结构时,but,except,besides后的不定式to也省略。Wecan’tbutadmirehisbravery.Wecan’tchoosebutwait。Sheissuchalovelygirlth
6、atIcan’thelpbutloveher.注意:but作“除了…以外”解时,若前面部分有do,did,done时,but之后接dosth.反之,后接todosth.Hecandonothingbutwait.Hewantednothingbuttoplayinthepark.3.作表语动词不定式作表语,一是主语有不定式充当;二是主语由抽象名词充当。Toteachistolearn.Myjobistohelpthepatient.【注意】如果在主语中(通常在主语从句或修饰主语的定语从句中)又实意动词do时,
7、作表语的动词不定式省略to。AllIwanttodonow(WhatIwanttodonow)isfillmystomach.4.作宾语不足语【注意】在感官动词(see,hear,feel,listento,notice,watch,observe等)和使役动词(let,have,make)后的补足语中,不定式不带to。但这类句子变成被动语态时,必须带to。Isawhimplayinthepark.→Hewasseentoplayinthepark.Thebossmadethosemenworkdayandn
8、ight.→Thosemenweremadetoworkdayandnight.Hewasseentobreakthewindow.可后接动词不定式作宾补的动词有:advise,allow,ask,hear,order,see,tell,want,wish,expect,watch等。①Thedoctoradvisedhernottoeattoomuchsugar.②Iwishyoutogototh