Unit 3.The way we are 单元语法课件（不定式用法） -高一英语下学期同步精品课堂（上教版2020必修第三册）

Unit 3 The way we are 必修三 上教版 2022 1 语法精讲 动词不定式infinitives 2 To learn the function of infinitives in a sentence To use infinitives to complete the exercises 3 不定式:是一种非谓语动词。 1.非谓语动词:是指那些在句中不能单独充当谓语的动词， 2.动词不定式在句中可以作句子除谓语之外的任何句子成分。 3.动词不定式的被动形式除了一般形式外还有其完成式和进行式。 不定式的定义: 4 不定式的形式: 一.基本形式： to+动词原形 二.其否定形式是:“not/never to do”/not do. 三.不定式可带宾语或状语构成不定式短语，没有人称和数的变化。 主动语态 被动语态 一般式 进行式 完成式 完成进行式 to do to be done to be doing to have done to have been done to have been doing --------- --------- 5 判断下列不定式在句中作何成分 1. It is our duty to clean the room every day.. 2. I hope to find a good job in a foreign company. 3. My dream is to be an artist. 4. The new hospital to be built is near the factory.. 5. We found it difficult to work with him. 6. We saw him to enter the building and go upstairs.. 7. He is looking for a room to live in. 8. I study hard to serve the people well. 9.To cath the early bus, she got up early. 6 不定式作主语通常位于句首，表示具体的某次动作，谓语动词用单数。 e.g. To see is to believe. 百闻不如一见。 To get up early is necessary. 早起是必要的。 ______________ is very important for everyone in society.  学习一项技能对社会上的每个人都很重要。 ______________________in a month is difficult. 要在一个月内完成这座建筑是困难的。 不定式作主语 To learn a skill To finish the building 7 2. 动词不定式与疑问词who, whom, whose, what, which, when, where, how等连用构成不定式短语，也可作主语。 e.g. 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。 不定式作主语 8 3. 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。 e.g. It’s not easy to work out the problem. = To work out the problem is not easy. 计算出这道题不容易。 It is interesting ______________________. 冬季里玩雪是很有趣的。 It is terrible ______________________________. 目睹轮船沉入大海，真是太可怕了。 不定式作主语 to play with snow in winter to see the ship sinking into the sea 9 it作形式主语代替真正主语不定式常见于以下情况中： It is + adj. + for/of sb. to do sth. It is + n. + (for sb.) to do sth. It takes/took/will take sb. some time/money to do sth. 【温馨提示】 不定式作主语 10 常用于表示事物的特征，用于此句型的形容