内容正文:
Section Ⅱ Learning About Language
(见学生用书P27)
动词不定式(短语)作主语
Ⅰ.用所给词的适当形式填写下面教材中的句子,并体会其语法特征。
1.(教材P14)However, during this period, it can be easy for some of them to form (form) bad habits.
2.(教材P14) To prevent (prevent) harmful habits like these from dominating a teenager's life is essential.
3.(教材P14) To change (change) bad habits is never easy, even with many attempts.
4.(教材P15) To facilitate (facilitate) a positive change in our bad habits, we must first examine our bad habit cycles and then try to adapt them.
5.(教材P15)After all, it is not easy to break (break) bad habits.
Ⅱ.根据以上例句填空。
1.句1、2、3、5为动词不定式短语作 主语 。
2.句4为动词不定式短语作 状语 。
3.句1、5中的it是 形式主语 ,真正的 主语 是后面的动词不定式短语。
动词不定式作主语通常表示个别的、具体的、一次性的或者具有将来含义的动作,并且句子谓语动词采用第三人称单数形式。常见的不定式作主语的情况主要有三类:
一、不定式直接作主语
不定式具有名词的特征, 可在句子中充当主语。
►To know something about English is one thing; to know English is quite another.懂一点英语是一回事; 掌握英语完全是另一回事。
►To love and to be loved is the greatest happiness one can get.
爱与被爱是一个人能获得的最大幸福。
►To look after these naughty boys is really difficult.
照看这些淘气的男孩真的很难。
[提示] 不定式和动名词作主语的区别:
(1)不定式作主语:表示具体的某次动作, 特别是将来的动作。
►To teach you the uses of the infinitive is my job today.(表具体行为)
教你们不定式的用法是我今天的工作。
(2)动名词作主语:表示比较抽象的、经常性的、一般性动作。
►Teaching is my job.(表抽象行为)
教学是我的工作。
[即时训练1]——单句语法填空
(1) To finish (finish) reading the book will take you two hours.
(2) To pay (pay) a visit to the Forbidden City is my dream.
(3)To improve people's lives and to speed up socialist construction are (be) two important tasks today.
(4)(2023·新高考Ⅰ) Taking (take) responsibility for mistakes is a positive step, but don't beat yourself up about them.
二、it作形式主语
1.It is+形容词(+for/of sb)+to do sth
►It is necessary for us to master a foreign language.我们有必要掌握一门外语。
►It is very kind of you to help us.
你帮助我们真是太好了。
[提示] 区别for 与of
(1)for sb 的句型常用来表示事物的特征, 其前常用表示客观形式的形容词, 如easy, hard, difficult, interesting, impossible等。
►It's very hard for him to study two languages.
对他来说学两门语言是很难的。
(2)of sb 的句型一般用表示人物的性格、品质, 其前常用表示主观感情或态度的形容词, 如good, kind, nice