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

Unit 1 Art Grammar : 不定式作表语 To know the usage of infinitive as predicative 动词不定式（to do ）和动词-ing形式（doing），过去分词（done）一样都是非谓语动词，即在句子中不能充当谓语；可以作除谓语以外的其他任何句子成分，即主语，宾语，表语，定语，状语，补语 不定式的定义： 判断下列句子中不定式所作的成分： 1.To see is to believe. 2.We can’t affort to buy this house. 3.His dream is to become a scientist. 4.I need a pen to write with. 5.To acquire knowledge , one must study. 6.She helped children to attend the schools. 主语 表语 宾语 表语 定语 状语 宾补 不定式的形式： 肯定：to do ；否定： not to do She slept downstairs in order not to disturb his son. 不定式的时态和语态： 类别 主动语态 被动语态 意义 一般式 to do to be done 发生在谓语动词之后 完成式 to have done to have been done 发生在谓语动词之前 进行式 to be doing / 正在进行 完成进行式 to have been doing / 一直持续 不定式充当表语 主动 将要 1）主语是表示意向、打算、计划等的词，如aim，purpose, wish, idea, task, plan，decision，choice，duty, dream, job等词时，常用不定式作表语。 不定式作表语用法 eg   His wish is to be a doctor in the future. His task is to correct these papers. The purpose of the book is to provide a complete guide to the university. Her dream is to make a movie. The old man’s job is to take care of the flowers in the garden. 2)主语为what引导的主语从句时，表语多用不定式。 What you should do next is (to) help him with his English。 注意：当句子的主语中有实义动词do的某种形式时，作表语的不定式可以省略to The only thing he can do now is (to) give up the plan. The thing for us to do is (to) accept the challenge. 3)不定式作表语时，一般紧跟在连系动词后面，如be, seem, remain, appear, get, prove, grow等，表将来的动作或解释说明主语的内容。 Mary doesn’t seem to like the idea. A use of the computer network is to send e-mail. 4)动词不定式作表语:表示目的。 Our goal is to increase the production by 20%. 5）动词不定式作表语:表示计划和安排，相当于be going to do. eg： They are to get married next month. 6)动词不定式作表语:表示“劝告，命令，禁止”，相当于can, may, should, must等情态动词。 You are to be back home by 10 o’clock.(=must) Such books are to be found in the school library. (=can/may) 7）用于条件状语从句中，表示”想要”，相当于want to do. If you are to remain friends, you must speak out. If you are to make progress, you had better work even harder. 1.Read the text again and underline all sentences of infinitive