:高中英语动词不定式、动名词用法要点讲解

高中英语动词不定式、动名词用法要点讲解

    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 compositionin a quarter of an hour.
    ④It＋be＋形容词＋of sb＋to do
    It is stupid of you to write down everything the teachersays.
    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,