Unit 2 Healthy Lifestyle Discover Useful Structures课件-2023-2024学年高中英语人教版（2019）选择性必修第三册

人教版 选择性必修三 Discover Useful Structures The infinitive of the verb used as the subject Unit 2 Healthy Lifestyle 1 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 neighbours with loud music last night. 语法感知 n. 外科医生 n. 外科手术 n. 解放军 剃掉胡须 Look at the following sentences and pay attention to the italicized infinitives. Find more infinitives in the reading passage, and tell their meanings and functions. 5. To prevent harmful habits like these from dominating a teenager's life is essential. 6. It can be easy for some of them to form bad habits. 7. After all, it is not easy to break bad habits. 总结： 1. 以上句子中动词不定式都是作 。 2. 句(2)(3)(4)(6)(7)中it作 ，真正的主语是后面的 。 More infinitives in the reading passage： 主语 形式主语 动词不定式 不定式作主语基本用法： 一. 动词不定式作主语，位于句首，谓语动词用单数。 1. To know yourself is difficult. 了解自己是很难的。 2. 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。 3. To look after these naughty boys is really difficult. 照看这些淘气的男孩真的很难。 4. To save money now seems impossible. 现在存钱好像不可能。 一、单一概念的动词不定式作主语时，谓语动词用单数。 4 二. 为了避免头重脚轻，常用it作形式主语放在句首，作主语的不定式常置于句末。 1. It's our duty to take care of the old. 照顾老人是我们的责任。 2. It took me two months to finish the work. 我花了两个月时间来完成这项工作。 3. It is against my principles to do such a thing. 做这样的事违背我的原则。 4. It is difficult to solve the problem. 解决这个问题很难。 5 5. It was hard him to live on his small income. 依靠他那点工资维持生活很难。 6. It was careless you to leave your umbrella on the train. 你真粗心，把伞忘在火车上。 在 It is+adj.+for sb to do...句型中，这类形容词常表示动作的特征， 比如：easy ,difficult, comfortable, pleasant, dangerous， tiresome, interesting , heavy等。 在 It is+adj.+of sb to do...句型中，这类形容词常表示人的性格、品质，如good，kind，nice，foolish，polite，considerate，careless等。 for of 注意： 6 三. 疑问词how, what, when,