Period Two Learning about Language 动词不定式的用法(Ⅰ)动词不定式的基本形式是“to+动词原形”,有时 to 可以省略
动词不定式(或不定式短语)没有人称和数的变化,在句中不能作谓语,但它可以有自己的宾语和状语,在一起构成不定式短语
动词不定式(短语)具有名词、形容词和副词的特征,其句法作用如下:1.作主语To build the Great Wall took them many years
建成万里长城花费了他们许多年时间
To play tricks on others is wrong
捉弄别人是不对的
作主语用的动词不定式(短语)常常用 it 替代,是先行主语或形式主语,真正的主语——动词不定式(短语)放在后面
上面两句可改写为:It took many years to build the Great Wall
It is wrong to play tricks on others
2.作宾语在begin,continue,hope,decide,want,wish,try,learn,afford,agree,determine,expect,fail ,manage ,offer,refuse 等动词后通常用不定式作宾语
Doctors tried to save his life
医生们试图挽救他的生命
某些及物动词后不能接动词不定式作宾语,只能用动词的ing 形式作宾语,这样的动词有avoid,advise,admit,consider,escape,enjoy,finish,mind,miss,risk,suggest,practise,excuse,imagine,keep 等,词组 can’t help,put off,give up,look forward to 等
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