Unit 1 Discover Useful Structures课件 -2022-2023学年高中英语人教版（2019）选择性必修第三册

Infinitives Used as Subject and Predicative 动词不定式作主语和表语 主备人：陈依文 修改人：Amelia 备课时间：2023年1月 上课时间：2023年2月 1 Learning objectives Understand the function and meaning of the infinitive when used as a predicate. Distinguish the difference between -ing form and infinitive constructions Review the use of infinitives as object, object complement, attributive, adverbial and use this structure correctly to describe the relevant content. Lead in Infinitive—to do 作定语 作状语 Introduction To be a doctor is hard. (不定式作________ ) His work is to drive a car. (不定式作________) I want to tell you a story. (不定式作________) She was the last student to leave the classroom.(不定式作______) Tell him to leave here next week.(不定式作_______) 主语 表语 宾语 定语 宾语补足语 动词不定式不能单独作谓语，可以作主语、宾语、表语、定语、补语等。 5 Infinitives as the Subject 不定式作主语 节标题页? 6 1. 动词不定式作主语，表示具体的、一次性的或者表示将来含义的动作，且谓语动词常用_______。如： To be calm in danger is very important/significant. To win the game is possible. To see is to believe. To work with him is a great pleasure 2. 动词不定式短语作主语时，为了保持句子平衡，往往用__作形式主语，而将动词不定式短语置于句末。如： It is important to learn English well. 单数 Presentation it 7 It做形式主语，其常见句型如下： 1. It＋is＋名词＋to do sth It’s our duty to protect the natural environment. 2. It took sb some time/money＋to do sth It took us three hours to finish the report. 3. It＋be＋形容词＋for/of sb＋to do sth It’s very generous of you to donate us a large sum of money. It is necessary for children to form good habits at an early age. 4. It seems/appears＋形容词＋to do sth It seemed impossible to catch up with them in 20 minutes. 8 It takes...to do... 需要……做…… It is wise of sb. to do sth. 对某人来说做某事是明智的 It is beneficial for sb. to do sth. 对某人来说某事是有益的 It is advisable to do sth. 做……是明智的. ... It is better to do sth. 最好做…… It is a good idea to do sth. 做....是个好主意 It is practical for you to do sth. 做. ...是可行的 It is important ecessary \ easy\hard for sb. to do sth.... 做某事对某人来说是重要的\必要的\容易\难的.... 常见表达 9 1. I