M5U1语法——动词不定式【附练习题 答案】.doc

第 PAGE 8 页 共 NUMPAGES 11 页 M5U1语法——动词不定式【附练习题+答案】 动名词的构成形式 动词不定式是由 “ to + 动词原形” 构成；动名词由动词+ing构成。 主动式有： 一般式、进行式、完成式和完成进行式； 被动式有： 一般式、进行式和完成式。 时态 语态 主动 被动 一般式 动词不定式 to do to be done 动名词 doing being done 进形式 动词不定式 to be doing to be being done 动名词 doing being done 完成式 动词不定式 to have done to have been done 动名词 having done having been done 完成进形式 动词不定式 to have been doing 动名词 having been doing 动词不定式、动名词用法要点讲解 一．做主语 ???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： ??? ① It＋be＋名词＋to do ??? Its our duty to take good care of the old. ??? ② It takes sb. + some time + to do ??? How long did it take you to finish the work? ??? ③ It＋be＋形容词＋for sb.＋to do ??? It is difficult for us to finish writing the composition in a quarter of an hour. ??? ④ It＋be＋形容词＋of sb.＋to do ??? It is stupid of you to write down everything the teacher says. ??? ⑤ It 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 动名词做主语 ??? Learning without practice is no good. ??? 动名词做主语时，也常用It句式。如： ??? ① 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. ??? ② 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，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. ??? ③ There is no + doing ??? There is no saying what will happen next. There is no denying that he has stolen the bike.??? 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