Unit 4 Space Exploration 动词不定式作定语和状语课件-2022-2023学年高中英语人教版（2019）必修第三册

动词不定式 动词不定式的句法功能 动词不定式的结构: to + 动词原形 不定式可以在句子里面充当主语，表语，宾 语；不定式还可以在句子中充当定语,补语, 状语。 动词不定式结构中含有动词，因此具有时 态，和语态上的变化，有的时候还会关联到 逻辑主语. 1 动词不定式做主语 动词不定式做主语，谓语动词用单数. 主语的位置有2种: 1) to do 位于句首 To finish the job will take me a week. 用 it 做形式主语， 真正的主语放在句尾. It is + 名词 + to do It is our duty to guarantee students’ safety. ii) It take sb + time + to do It took me a week to finish the job. iii) It is + adj. + for sb to do It is dangerous for children to cross the street. 这一类形容词修饰动作：difficult, easy, hard important, impossible 等 iv) It is + adj . + of sb to do It is kind of Tom to help me. 这一类形容词修饰人: clever, selfish, silly, stupid，kind等。 It is kind of Tom to help me.= Tom is kind to help me. 2. 动词不定式做宾语 to do作宾语的词有以下3类 动词+ to do afford, agree, arrange, attempt, choose, decide，demand, determine, expect, hope, learn, fail ，help (to常常省略), manage, offer, plan, prepare, pretend, promise, refuse, seek, threaten. Tom threatened to appeal to a higher court. Doctors should learn to be patient. Tom sought to find out his money previously hidden in the shoes, but he failed. （seek to 力图,试图） 2) 动词+ 疑问词 + to do 这一类词动词是：decide, know, consider, see, forget, learn, remember, show, understand, hear, wonder, find out, explain, tell . I don’t know when and where to hold the meeting. You can choose what to do but you should explain how to do it. 3) 如果是动词+宾语+宾补， 宾语如果是动词不定式那么就用it 做形式宾语，to do 放在句尾. Tom feels it his duty to help the poor. I find it easy to learn French. 3 动词不定式做表语 不定式作表语表示具体动作或将来动作；动 名词作表语表示抽象的一般行为。 尝试比较以下2个句子. My work is to clean the room this evening. My work is teaching you. 1) 当主语包含 aim, duty, hope, idea, mistake, plan, purpose, suggestion, goal, dream, ambition 等词时, 要用不定式作表语 My ambition is to become a pilot. My current aim is to improve my oral English. 2) 当主语是to do 表语也用to do To be kind to enemy is to be cruel to yourself. To see is to believe. 1) consider(=find), imagine, think(=feel), believe, discover, suppose 等表示心理状态的词. (还包括prove vt) I believe him to be re