1、第四课时Grammar不定式作主语Teaching objectivesLearn the grammatical content of the infinitive as subject and can use it skillfully【课前预习】合作探究阅读下列句子，体会动词不定式的用法。To see is to believe.百闻不如一见。It is interesting to play with snow in winter.冬季里玩雪是很有趣的。Its important for human beings to keep the balance of nature.保持自然平衡
2、对人类来说很重要。自主发现不定式是非谓语动词的一种，没有 和 的变化，在句中可以作 (有名词和代词的作用)，通常表示 、 行为。【课内探究】一、用法不定式位于句首To study English well is not easy.学好英语不容易。it作形式主语，把不定式(短语)置于句末。为了避免头重脚轻，可用it作形式主语，把不定式(真正主语)放到句子后面。It would be a great honor for me to invite you to come to China.邀请你来中国对我来说是一件非常荣幸的事。As we all know，it is good for your h
3、ealth to stop smoking.众所周知，戒烟益于健康。二、动名词和不定式作主语的区别一般来说，不定式作主语表示一次性的、具体的动作，而动名词作主语表示一种抽象的和泛指的动作。To lie is wrong.说谎是错误的。(对于说谎者是谁，说话人心中是有所指的)Swimming is good exercise.游泳是一项很好的锻炼。(指游泳这项运动)巩固练习：It takes about ten minutes .步行去银行大约用十分钟时间。Its important for you l.对你们来说学好外语非常重要。Its very kind .你这样说真是太好了。It must
4、 be great fun .乘宇宙飞船飞往月球一定很有趣。 hasnt been decided yet.什么时候开会还没有定下来呢。注意：不定式与疑问词how, what，when，where, which等连用构成不定式短语，也可作主语。How to use the computer is a question.如何使用计算机是个问题。【课后巩固】.用括号内所给动词的适当形式填空1.It is wise (take) such gifts with gratitude.2.He will find it is easy (make) friends in this city.3. (ge
5、t) there by bike will take us half an hour.4.It is an offence (drop) litter in the street.5.When (leave) for London has not been decided yet.6.Its necessary for you (lock) the car when you do not use it.7. We cant afford _ (live) in such a big house. 8. The man expects his wife _ (bring) him breakfa
6、st in bed at weekends. 9. Afraid of _ (bite) by snakes, the boy was afraid _ (touch) them. 10. James Watt is known _ (invent) the steam engine.11.The book was said _ (translate) into German in 1946.12.The meeting _ (hold) tomorrow is of great importance. 13.A quarrel seems _ (break out) between the
7、two women and they are still glaring at each other now. .补全句子1. is a good habit.每天读书是个好习惯。2. is nice.和他们交朋友真是令人愉快。3. to do me a favour.你能帮助我真是太好了。4. does good to your health.晚饭后散步对健康有好处。5.It is impossible for lost time .弥补失去的时间是不可能的。6.It is difficult for us in a quarter of an hour.语法填空Mike drove to
8、a remote border town alone. He didnt stop the car 1. _ (take) a break although he was feeling tired. As a result, a traffic accident occurred, which caused him 2. _ (trap) inside the car. Fortunately a girl who happened to pass by volunteered 3. _ (save) him, only 4. _ (find) Mike was completely loc
9、ked in the car. After calling an ambulance, she managed 5. _ (give) him first aid, using the method she had learned at school. Soon, Mike was rushed to hospital in an ambulance. It took him three months 6. _ (recover) from his injuries. The girl named Mary felt pleased 7. _ (do) such a great thing,
10、though she realized the car may have exploded. When interviewed, she said, “Ive also met with a traffic accident. A kind passer-by saved my life but he was killed. I was the only one 8. _ (survive) the crash. The man was said 9. _ (work) on the road helping people in need for ten years. I was too moved even to speak when hearing the story. Therefore, I determined 10. _ (stay) here and give people in need a helping hand.”4
