（1）基本形式：to+动词原形（在某些情况下可以不带to）（2）特点：A.A.没有人称和数的变化没有人称和数的变化C.有时态和语态的变化（被动语态的形式为tobe+动词过去分词）B.可以有自己的宾语和状语动词不定式AA、作主语、作主语Tolearnaforeignlanguageisnoteasy.Itisgoodothers.帮助他人是件好事。ItisexcitingtheInternet.上网是件令人兴奋的事。tohelptohelptosurftosurf=It’snoteasytolearnaforeignlanguage.动词不定式用法B、作表语TheimportantthingisTheimportantthingistofinishtheworktofinishtheworkontime.ontime.WhatyouhavetodonowisWhatyouhavetodonowis((打扫教室打扫教室))tocleantheclassroom动词不定式C作宾语动词+todo见动词有choose,hope,offer,want,decide,arn,plan,wish,agree,fail等1.Hedecided(buy)thecamera.tobuy2.Iwant(listento)somemusicafterclass.tolistento3.Ihope(travel)allovertheworldoneday.totravel动词不定式2)动词+疑问词+todoIdon’tknowIdon’tknowwhattodo.whattodo.howtodoit/that.howtodoit/that.((去哪里去哪里))((什么时候出发什么时候出发))((选择哪个选择哪个))WheretogoWheretogoWhentoleaveWhentoleaveWhichonetochooseWhichonetochoose动词不定式PartAonP7PartAonP7WedecidedtomeetVivientoday.We_______WedecidedtomeetVivientoday.We_______(want/help)helpinsomeway.Whenwe(want/help)helpinsomeway.Whenwearrived,Vivienwasveryhappy.She________arrived,Vivienwasveryhappy.She________(begin/talk)tomeaboutherschool.Shesaid,(begin/talk)tomeaboutherschool.Shesaid,““I____________(like/go)toschool,butII____________(like/go)toschool,butIdon’thaveanyfriends.Ifeellonely.”don’thaveanyfriends.Ifeellonely.”Mumgavehersomeadvice.ThenMumaskedMumgavehersomeadvice.ThenMumaskedmetogiveVivienherpresent,butI________metogiveVivienherpresent,butI________(forget/bring)it!Viviensaid,“It’sOK.I(forget/bring)it!Viviensaid,“It’sOK.I__________(hope/see)youagainsoon.”__________(hope/see)youagainsoon.”wantedtohelpwantedtohelpbegantotalkbegantotalkliketogoliketogoforgottobringforgottobringhopetoseehopetosee3)动词+it(形式宾语）+宾补+todoIfinditimportanttolearnEnglish我发现很难和他好好相处.我发现在炎热的夏天很容易入睡Ifindithardtoget...
