不定式---
不定式的构成
式｜态
主动语态
被动语态
一般式
towrite
tobewritten
完成式
tohavewritten
tohavebeenwritten
进行式
tobewriting
?
完成进行式
tohavebeenwriting
不定式的句法功能
作主语Tohearfromyouisnice.
不定式作主语时，为了保持句子的平衡，往往以it作形式主语，而不定式置于谓语动词后。如：It’snicetohearfromyou.
作宾语通常用于afford,agree,aim,arrange,ask,attempt,choose,continue,dare,decide,demand,desire,determine,expect,fail,hate,help,hesitate,hope,intend,learn,long,love,manage,mean,need,offer,plan,prefer,prepare,pretend,promise,prove,refuse,seek,threaten,trouble,wait,want,wish
Iforgottolockthedoor.Pleaseremembertowritetome.
作表语Myjobistopickupletters.
作定语须放在被修饰的名词之后Heisalwaysthefirstonetogetup
主动表被动Ihaveabooktoread.
作宾补通常用于advise,allow,ask,beg,cause,challenge,convince,enable,encourage,expect,forbid,force,instruct,invite,order,permit,persuade,recommend,remind,request,require,teach,tell,train,urge,want,warn等词后。如：Heorderedhertoleaveatonce.
作状语Hegotupearlytocatchthefirstbus.
作独立成分tobehonest,tobeginwith,tostartwith,totellyouthetruth
Totellyouthetruth,Itoldalie.Tobegin/startwith,let’ssingasong.
“疑问词＋不定式”结构。如：Idon’tknowhowtochoosethem.
不定式复合结构ItisimportantforustolearnEnglishwell.
但当表语表示不定式的逻辑主语的特征属性时要用of如：good,kind,nice,wise,clever,silly,stupid,foolish,right,wrong,rude,impolite,careless
Itisverykindofyoutohelpme.=youarekindtohelpme.
too…to结构。如：Hewastooexcitedtogotosleep.
动词不定式省略省略towatch,see,notice,observe,lookat,hear,listento,feel,make,let,have但getsbtodo注意：主动省to,被动加to。
donothingbut
Ididnothingbutsleep.Iwanted/chose/desirednothingbuttosleep.
两个或两个以上的不定式并列在一起时，第一个不定式带to，后面的不定式往往把to省去。Iwishtofinishmytaskand(to)getaway.但表对照，不能省toItisbettertolaughthantocry.
省略动词部分,为避免重复，口语中常可省去与前边动词重复的动词原形而留下to。
---Wouldyouliketogotothefilmswithme?---I’dliketo.
inorderto,so