【正文】
和狀語(yǔ)等多種成分。動(dòng)詞不定式的肯定形式是to+do;其否定形式是not to+do。 1.作主語(yǔ) 可以直接作主語(yǔ)。如: It39。s our duty to keep our environment clean and tidy. 點(diǎn)擊規(guī)律:動(dòng)詞不定式在句中作主語(yǔ)時(shí),常放在It is +adj +(for sb.)+(not)to do sth句型中,表示說(shuō)話人對(duì)客觀事件的決斷,意為:做…..是……的,it僅作形式主語(yǔ),真正的主語(yǔ)是to do sthIt is very interesting to It is useful to It is healthy to run every It is a little difficulty for me to work out this It is bad not to finish It is bad to be late for It is+adj+of sb +(not)to do sth該句型通常表示說(shuō)話人對(duì)客觀事件的驚訝、興奮、懊悔、難過(guò)等感嘆情緒,與It is +adj +(for sb.)+(not)to do sth的意義不同。類似的詞有:careless,careful,clever,considerate,foolish,good,impolite,kind, naughty,nice,silly,stupid,friendly因此區(qū)分是用It is +adj +(for sb.)+(not)to do sth還是It is+adj+of sb +(not)to do sth,要清楚adj修飾的是sb還是to do sth例如:It is nice for me to have breakfast with you(nice是指have breakfast with you這件事)對(duì)于我來(lái)說(shuō),能和你一起吃早餐真好。 2.作賓語(yǔ) a.want,decide ,agree,afford, agree, aim, appear, ask, believe, care,claim,decide ,demand, desire, determine, expect, fail, happen, hesitate, hope, intend(有打算), learn, long(渴望), manage, offer, pretend, promise, prepare, refuse, seek, swear(發(fā)誓), undertake(承擔(dān)),want, wish等動(dòng)詞后面跟并且只能跟不定式。 點(diǎn)擊規(guī)律:上述動(dòng)詞后面除接不定式外,還可以接動(dòng)名詞,意思無(wú)很大區(qū)別。如: I like swimming,but I don39。 c.stop,forget,remember,go on ,try等詞或短語(yǔ)后面可以接不定式。 提示板: 1)stop to do sth.:停止一件事,去做另一件事。 2)forget to do sth:忘記要去做某事(未做) forget doing sth:忘記做過(guò)某事(已做) 3)remember to do sth:記得去做某事(未做) remember doing sth:記得做過(guò)某事(已做) 4)go on to do sth:接著做另一件事(接下去做與原來(lái)不同的一件事) go on doing sth:繼續(xù)不停的做某事或間斷后繼續(xù)做原來(lái)沒(méi)有做完的事 5)try to do sth:試著做某事(實(shí)際上意思是努力想做成某事eg:I tried to escape,but I ,但是沒(méi)有成功) Try doing sth:試著做某事(實(shí)際上是為了達(dá)到另外一個(gè)目的,So hot here,isn39。 “恩,就是?!保? 例句:When the teacher came in,the students stopped talking;when he came out,the students stopped to talk. 當(dāng)老師走進(jìn)來(lái)時(shí),學(xué)生們停止說(shuō)話;當(dāng)老師走出去時(shí),學(xué)生們又開(kāi)始說(shuō)話。就是說(shuō)不定式由it代替,把不定式放到后面去。如: