语法语法infinitiveinfinitive不定式的结构形式语态形式主动被动一般式完成式进行式完成进行式todotobedonetohavedonetohavebeendonetobedoingtohavebeendoing否定形式nottodoinfinitiveinfinitive不定式的用法1.Itisrighttogiveupsmoking.2.Shewantedtoborrowmybike.3.Icameheretoseeyou.4.Heneedsaroomtolivein.5.Iaskedhimtodotheworkwithme.6.Mywishistobecomeadoctor.主语宾语状语定语宾补表语(1)作主语不定式短语作主语时，往往放在谓语之后，用it作形式主语。Toseeistobelieve．Togiveupsmokingisright.Itisrighttogiveupsmoking.It’sfoolish(ofyou)todothat.It’simpossible(foryou)tofinishall.不定式作表语1.主语是不定式(表示条件)，表语也是不定式(表示结果)Toseeistobelieve.Toworkmeanstoearnaliving.2.主语是以aim,duty,hope,idea,happiness,job,plan,problem,purpose,thing,wish等为中心的名词，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Hiswishistobuyacarinthenearfuture.WhatIwanttosayistogetridoftheplanforever.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；“另一种是动词＋疑问词＋带to”的不定式1.动词＋带to的不定式结构能跟动词不定式的动词，常见的有：want,like,prefer,try,ask,afford,agree,determine,expect,fail,hope,intend,manage,mean(想要),offer(表示愿意做…),pretend,promise,refuse,seek(试图),undertake,wish(想要)等。Iexpecttoseeyoutomorrow.HeofferedtohelpmewithmyEnglish.2.动词＋疑问代(副)词＋不定式常见的有：advise,decide,discuss,findout,forget,know,learn,remember,see,teach,tell,think,understand,wonder等。疑问代(副)词有what,when,where,which,how,whether等，但不包括why，Hedoesnotknowhowtogotherewhentospeakbeforeus.who(m)tovisit.whichonetochoose.Youcandecidewhethertogoorstayhere.whentoseeadoctor.3.有时不定式用it来代替，而把不定式放到后面Hemakesitaruletotakeawalkbeforebreakfast.Ithinkitinterestingtoplayfootball.Sheconsidersitimportanttomakefriends.4.有时THERE和TOBE“”“连用表示有或存在(某情况)”等Itisimpossiblefortheretobeanymore.Iexpecttheretobenoargumentaboutthis.Heaskedmetodotheworkwithhim．但是在feel,hear,listento,lookat,notice,observe,see,watch,have,1et,make等词后的补足语中，不定式不带to。但变成被动语态时,被省的to必须加上。e.g.Whentheywereyoung,heoftenmadehislittlesistercrybutnowheismadetodothisorthatbyhissister.作宾语补足语不定式作定语1.不定式作定语修饰名词或代词时后置Ihavesomethingtotellyou.如果不定式动词是不及物动词，要在动词后加上相应的介词:Ihadgotnoplacetolivein.Thatgirlhasnothingtoworryabout.Shehasfourchildrentolookafter.Ineedsomepapertowriteon.Iwantapentowritewith.2.所修饰的名词前有thefirst/last/next,theonly,thebest,themost等序数词或最高级等修饰语时，用不定式作定语。不定式修饰something,anything,nothing.Iwantsomethingtoread.Heistheonlypersontoknowthetruth.作状语:表示目的\结果或原因等.1.表目的:常用的结构有:todo/inorderto/soastoTocatchthebus,Ihavetogetupearly.Shecheckedthenamescarefullysoastoavoidemistakes.Inordertoarrivebeforedark,westartedearly.2.表示结果Theboyisoldenoughtogotoschool.Shewenthomeverylate,only(just)tofindeverythingstolen.(与only连用，表示意外的不好的结果）还有固定搭配表示结果：so…asto;such…asto…;enoughto…;too…to…Wehavesomuchfoodastotreatourguests.Isthatroombigenoughtoseatallofus?Heistooyoungtofitthatjob.3.表示原因:不定式用来说明产生这种情绪的原因,用于此结构有:happy,lucky,sorry,anxious,proud,disappointed,angry,surprised,ready,delighted,clever,foolish,pleased,fortunate,right等.It'sverykindofyoutosayso.Iamprettypleasedtohearthenews。I'msorrytointerruptyou.Theyarequitesurprise...
