1、Section Learning About Language(动词不定式作主语)情境创设语法精讲见学用28页教材链接（1）（教材P14）However, during this period, it can be easy for some of them to form bad habits.（2）（教材P14）To change bad habits is never easy, even with many attempts.（3）（教材P15）After all, it is not easy to break bad habits.（4）（教材P16）Changing a bad
2、habit is difficult, and it is easy to make excuses and give up.观察上面句子，动词不定式在这些句子中作的是主语；it 在句中为形式主语。要点精析动词不定式作主语时，相当于名词或代词的作用，一般表示具体的、一次性的动作。1. 单个不定式作主语时，谓语动词通常用第三人称单数形式。两个或两个以上的不定式作主语时，若语意基本一致或不定式作为一个整体，谓语动词用单数；若语意不一致，则用复数。To get enough protein each day is beneficial to our health. 每天摄取足够的蛋白质对我们的健康有
3、益。To love and to be loved is sweet to us. 爱和被爱对我们来说都是甜蜜的。To improve peoples lives and to speed up social construction are two important tasks. 改善人们的生活和加快社会建设是两项重要任务。2. 动词不定式作主语时，若不定式太长，为避免头重脚轻，常用it作形式主语，将真正的主语置于后面。It is impossible to rely on your parents all your life.你不可能一辈子都依靠你的父母。It is essential
4、to reserve a table in advance of festivals. 在节日前预订桌位是有必要的。3. 常用句型（1）It is+adj.+（for/of sb.） to do sth.如果形容词表示的是不定式的逻辑主语的性质、身份、特点，如careless, clever, good, kind, foolish, honest, lazy, nice, silly, wise等，用介词of。如果形容词表示的是事物或行为的特点或性质，如difficult, easy, hard, important, impossible, necessary, inconvenient,
5、 essential 等，用介词for。It is impolite of you to disturb others. 打扰他人是不礼貌的。It is difficult for us to finish writing the composition in a quarter of an hour. 在十五分钟内写完这个作文对我们来说太难了。（2）It is+n.+to do sth. 做某事是It is a hard task to change long habits in a short time.要在短时间内改掉长期养成的习惯是一项艰巨的任务。It is a doctors dut
6、y to heal the wounded and rescue the dying. 救死扶伤是医生的职责。（3）It takes/took sb. some time to do sth. 做某事花费某人多长时间It takes us nine years to build the Hong Kong-Zhuhai-Macao Bridge. 建造港珠澳大桥花费了我们9年的时间。It took me more than an hour to do my homework yesterday. 昨天我做作业用了一个多小时。实战演练. 单句语法填空1.（2020课标全国）It is tradi
7、tional to bring (bring) a gift to a housewarming party.2.（2020课标全国）Its hard to tell (tell) exactly how many people agree with him, but research indicates that the numbers have been rising for some time.3.（2020江苏）The implication of these results is that to gain the greatest health benefits from exerc
8、ise, it may be wise to skip (skip) eating first.4.（2019课标全国）It is difficult to figure (figure) out a global population of polar bears.5.（2019天津）Then we will know how important it is to have meaning in our life.6.Coming out of this experience, I realize its OK to be (be) different from others.7.It wa
9、s impolite of you to speak to an outstanding teacher like this.8.It took years of work to reduce (reduce)the industrial pollution and clean the water.9.Its very important for the new comers to study some rules.10.To lose heart means (mean) failure. 完成句子1.我认为你问面试会持续多久是不礼貌的。(impolite)I think it is imp
10、olite of you to ask how long the interview will last.2.她花了一个多小时的时间来分析这些有助于她写研究报告的数据。(analyze) It took her more than an hour to analyze the data which helped her write research reports.3.事实上，一开始就进行太多的锻炼对你的身体健康是有害的。（不定式作主语）Actually , to start with too much exercise is bad for your physical health.4.汤姆
11、很固执，所以你要说服他改变主意是很不容易的。(persuade sb. to do sth. ; change ones mind)Tom is stubborn, so its not easy for you to persuade him to change his mind .5.那位老人无私地把食物送给街上无家可归的人。(selfless; give away)Its selfless of the old man to give away food to the homeless in the street.6.父亲批评了我并告诉我捉弄别人是错误的。(play tricks on
12、sb.)Father criticized me and told me it was wrong to play tricks on others .7.成为一名专业的运动员不容易，需要日复一日的坚持。（不定式作主语） To be a professional athlete is not easy and it needs persistence day in and day out.8.无人驾驶汽车什么时候能够在道路上随处可见，这是很难预测的。（it作形式主语）It is hard to predict when driverless cars will be seen everywhere on the roads.9.对于外国人来说，能够自由使用筷子不是一件容易的事。(it is+n.+to do sth.)It is not an easy thing for the foreigners to use chopsticks freely.10.如今，很多人意识到教给孩子书写技巧是很有必要的。（it作形式主语）Nowadays, many people realize it is necessary to teach children the skill of handwriting.
