动词不定式、动名词用法要点讲解

1 / 4 动词不定式、动名词用法要点讲解 （山东日照广播电视大学 李莉） 动词不定式和动名词的句法功能比较： （附图 图 ） 一、作主语 不定式作主语 动词不定式作主语时，句子的谓语动词常用单数，其位置有以下两种： (1)把不定式置于句首。如： To get there by bike will take us half an hour. (2)用 it 作形式主语，把真正的主语不定式置于句后，常用于下列句式中。如： It be名词 to do Its our duty to take good care of the old. It takes sb+some time+to do How long did it take you to finish the work? It be形容词 for sb to do It is difficult for us to finish writing the compositionin a quarter of an hour. It be形容词 of sb to do It is stupid of you to write down everything 2 / 4 the teachersays. It seems(appears)形容词 to do It seemed impossible to save money. 在句型中，常用表示客观情况的形容词，如：difficult,easy,hard,important,impossible,necessary 等；在句型中，常用careless,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise 等 表示赞扬或批评的词。在不定式前的 sb，可看作其逻辑主语。这一句式有时相当于 Sb is形容词 to do 句式 ，如： Itskind of you to help me with my English.=You are kind to helpme with my English. 动名词作主语 Learning without practice is no good. 动名词作主语时，也常用 It句式。如： Its +no good(no use,fun,a pleasure,a waste of time)+doing Its no good reading in dim light. Its no use sitting here waiting. Its形容词 doing Its dangerous swimming in the sea in windy days. 这样用的形容词有 expensive,nice,tiring 等，3 / 4 但 important,necessary 则不适用于这种结构，应用不定式 代替，如： Itsimportant for you to keep fit. There is no+doing There is no saying what will happen next. 在这一结构中，动名词后常带宾语，相当于 Its impossible to 结构。 动词不定式和动名词作主语的区别 不定式作主语经常表示具体动作，常与特定的动作执行者联系在一起；而动名词作主语经常表示抽象动 作，经常不与特定的动作执行者联系在一起。如： Its no good eating too much fat. Its no good for you to eat so much fat. 动名词结构作主语，可以用名词或代词属格形式作逻辑主语。如： Its no use your pretending that you didnt know the rules. 二、作宾语 不定式作宾语 以下动词后，只能跟不定式作宾语。如：agree,ask,aim,arrange,choose,decide,demand,expect,fail ,help,hope,lean,long, manage,offer,plan,prepare,pretend,promise,refuse,4 / 4 wish等，这些词大部分可接 th at 引导的从句。 如： I decided to ask for my money back. I decided that I would ask for my money back. When our visit to the farm was over,we expected to startb