不定式和动名词的区别.docVIP

动词不定式和动名词的句法功能比较 一,作主语 ⒈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: ①It+be+名词+to do Its our duty to take good care of the old. ②It takes sb + some time +to do How long did it take you to finish the work ③It+be+形容词+for sb +to do It is difficult for us to finish writing the composition in a quarter of an hour. ④It+be+形容词+of sb +to do It is stupid of you to write down everything the teacher says. ⑤It seems(appears)+形容词+to do It seemed impossible to save money. 在句型③中,常用表示客观情况的形容词,如:difficult, easy, hard, important, impossible, necessary 等;在句型④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:Its kind of you to help me with my English.=You are kind to help me with my English. ⒉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: ①Its +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. ②Its+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,但important, necessary则不适用于这种结构,应用不定式 代替,如:Its important for you to keep fit. ③There 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. ⒊动词不定式和动名词作主语的区别 ①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. ②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 ⒈不定式作宾语 ①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, wish等,这些词大部分可接that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 start back on foot. Wh