(
课件网) UNIT 2 HEALTHY LIFESTYLE Discovering Useful Structures Read and Observe Pay attention to the red italicized infinitives and discuss the meanings and functions of the italicised infinitives. 1. To change bad habits is never easy. 2. It took the surgeon three hours to finish my mother’s lung surgery. 3.To join the People’s Liberation Army, it is required for men to shave off their beards. 4. It was not polite to disturb your neighbors with loud music last night. 主语 主语 主语 主语 动词不定式（短语）作主语 位置 直接放在_____作主语； 为了保持句子平衡，用_____作形式主语，放在句首，把真正的主语 — 动词不定式置于句后； 句首 it Observe To see is to believe. To get good grades requires a lot of hard work. To learn a skill is very important for everyone in society 1.不定式作主语通常位于_____，表示具体的某一次动作，谓语动词用_____。 句首 单数 用法 （2）两个或两个以上动词不定式并列作主语，若语意不一致则用 复数；但如果动词不定式作为一个整体或属于同一概念，仍 用单数。 To improve people’s lives and to speed up socialist construction are our two important tasks today. 提高人民生活水平和加快社会主义建设是我们当前的两个重 要任务。 Early to go to bed and early to rise makes a man healthy. 早睡早起有益健康。 2. 当主语较长，谓语较短时，常用it作形式主语放在句首，而将真正的主语—不定式放到谓语的后面。 It is not right for people with the virus to go to public places. It was not polite to disturb your neighbours with loud music last night. To join the People’s LiberationArmy , it is a rule for men to shave off their beards. It took the surgeon three hours to finish my mother’s lung surgery. 常用句型1：It is+adj.+for/of sb +to do sth 若adj. “描述人的品格、特点”, 用of,如 kind, nice, wise, silly, polite, impolite, friendly, foolish, clever; 若adj.“描述事或行为的特征”, 用for,如easy, hard, difficult, possible, important, impossible, necessary,good, bad, exciting, interesting, surprising It’s difficult for me to get up. It’s very kind of you to help me. Summary 例1. It is +adj.+(for sb) to do eg: It is easy for me to learn how to drive.学开车对我来说很轻松。 It is +adj.+(of sb) to do eg:It is clever of you to apply for the position. 你申请这个职位真是明智的。 例2. It is +n.+ to do sth( an honour, our duty, a pity, a shame) eg:It is our duty to take care of you. 照顾你是我们的责任。 例3. It takes/took sb some time to do sth. It takes me half an hour to do my housework. 我花了半个小时做家务。 不定式作主语，it 做形式主语的常见结构： 名师点津 在It is＋no use/no good/useless/a waste of time ...句型中常用动词-ing 形式作真正的主语。 It is no use waiting here doing nothing. 无所事事地在这里等待是没有用的。 3.动词不定式与疑问词who, whom, whose, what, which, when, where, how连用构成不定式短语做主语。 How to use the computer is the question. 如何使用计算机是个问题。 Where to go has not been decided. 去哪儿还没有定下来。 To look after children is her job today. 她今天的工作是看孩子。 Looking after children is her ... ...
