Unit 1 Period 3 Grammar and usage(精品课件)-高二英语上学期同步精品课堂（译林版2020选择性必修第一册）

Unit 1 Food matters Period 3 Grammar and usage 译林版英语选择性必修一 Lead-in Exploring the rules Below is a blog entry about eating out and eating at home. Find the sentences that use to-infinitives. Working out the rule When the to-infinitive is used as a subject, we usually use the preparatory subject at the beginning of the sentence. The to-infinitive can also be used as a predicative. It usually comes after the verb . it be 04 Conclusion 一个句子中已经存在一个_________, 又没有_______的情况下，另一个动词需要用____________。 He often works hard to earn more money. The meeting is to be held next week. → 动词不定式to do 在句中通常表示:____________和__________。 谓语动词 连词 非谓语动词 目的 将来 A Exploring the rules 动词不定式一般由“to+动词原形”构成，其否定形式是“not to do”。动词不定式可以带宾语或状语构成动词不定式短语，没有人称和数的变化，但有时态和语态的变化。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。如： To finish the task in a week is very hard. The big boy managed to pass the exam. My work is to clean the garden every day. She was the first woman to swim across the English Channel. Tell him to come here the day after tomorrow. 主 宾 表 定 补 A Exploring the rules To see is to believe. To help others is our duty. It is important to enlarge English vocabulary. It would be a waste of time to look up every new word when you read an English novel. 一、动词不定式作主语 2. 动词不定式短语作主语时，为了保持句子平衡，往往用it作形式主语，而将动词不定式短语置于句末。如： 动词不定式作主语，表示具体的、一次性的或尚未做的动作。如： 单个非谓语做主语表单数，谓语动词用三人称单数 A Exploring the rules It is important for children to tell right from wrong at an early age. It’s very kind of you to tell us what happened yesterday. 一、动词不定式作主语 3. “it+be+形容词+for sb to do sth”意为“做某件事对某人而言是……的”。 在该句式中的形容词多是说明性的，不用来指人或物的品质、特性，如 difficult、easy、hard、important、dangerous、impossible等。如： 4.“it+be+形容词+of sb to do sth”意为“某人做某事是……的”。该句式中的形容词用以叙述人的个性、品质，如kind、good、nice、clever、careless、polite、foolish等。如： 5.“it+be+名词＋to do sth”意为“做某件事是某人的……”。如： pity, shame, pleasure, one's duty, one's job, fun, joy, good manners, bad manners… It’s my job to help tackle online hate. I