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動詞不定式用法 動詞不定式?jīng)]有人稱和數(shù)的變化,在句中不能獨立作謂語。但動詞不定式具有名詞、形容詞和副詞特征,在句中可以作主語、賓語、賓語補(bǔ)足語、定語、表語和狀語等多種成分。另外,動詞不定式具有動詞特點,可以有自己的賓語和狀語,組成動詞不定式短語。動詞不定式的肯定形式是to+do;其否定形式是not to+do。 下面以動詞不定式在句中的作用來予以詳細(xì)說明。 1.作主語 可以直接作主語。如: To see is to believe. 但在英語中,常用it作形式主語,真正的主語即動詞不定式放在后面。如: It39。s wrong to play tricks on other people. It39。s our duty to keep our environment clean and tidy. 點擊規(guī)律:動詞不定式在句中作主語時,常放在It is +adj +(for sb.)+(not)to do sth句型中,表示說話人對客觀事件的決斷,意為:做…..是……的,it僅作形式主語,真正的主語是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該句型通常表示說話人對客觀事件的驚訝、興奮、懊悔、難過等感嘆情緒,與It is +adj +(for sb.)+(not)to do sth的意義不同。It is very kind of you to tell me the truth.你能告訴我事實,真是太好了It is stupid of him to do such a silly thing. 他做那件傻事,真是太笨了It is very clever of you to work out this question. 你能解出這道題目,真是太聰明了It is very wise of you to read this novel. 你看這本小說,真是太明智了這個句型中用介詞of而不是for的原因是這里的形容詞是用來形容人的品質(zhì)性格的。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)對于我來說,能和你一起吃早餐真好。It is nice of you to help him with his English.(nice是指you,形容人的品質(zhì))你幫他補(bǔ)習(xí)英語,真是太好了。 2.作賓語 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等動詞后面跟并且只能跟不定式。如: We agreed to start early. She wants to be a doctor. b.love,like ,begin,start,hate ,prefer等詞后面可以接不定式。 點擊規(guī)律:上述動詞后面除接不定式外,還可以接動名詞,意