英语语法动词不定式讲解学习

不定式
• 不定式的概述 • 不定式的基本用法 • 不定式的特殊句型
不定式
不定式是非谓语动词的一种，由“to+动 词原形”(to do)构成,动词不定式有动词 和名词的特征。不定式可以作主语、宾语 、状语、表语和定语等成分，但不能单独 作谓语。
• 2不定式的时态和语态
不定式的时态
• 现在时：不定式的一般现在时表示的动作 ，有时与谓语动词表示的动作同时发生， 有时发生在谓语动词之后；
• It is very kind of you to say this.
• It is very rude of you to do this.
翻译：
• 你这样子对待女孩子是很粗鲁的。
• It is very rude of you to do this to the girls.
• It is very rude of you to treat girls like this.
第20~21讲
非限定动词——不定式
非限定动词？
• 非限定动词又叫非谓语动词，包括不定式、分 词和动名词。
• 非限定动词和限定动词的区别 不同点：前者不能单独作谓语；不受主语人称 和数量的限制；而限定动词的形式要和主语 人和数一致。如；She likes to dance. They like to dance. 可以起名词、形容词、副词的作用。如： To see is to believe. The man sitting by her is my teacher. Seeing the teacher entering the room, I stood up.
（1）不定式所修饰的名词与不定式在逻辑上构成主谓 关系时，不定式用主动语态。
你有开门的钥匙吗？ key unlock the door Have you got a key to unlock the door?
（2） 不定式的逻辑主语是这个不定式动作的承 受者，来自百度文库定式用被动语态
He asked to be sent to work in countryside.
• 相似点： 1. 都可以带宾语。如； • He bought a computer. • He wanted to buy a computer. 2. 都可以由状语修饰。如； • He studies very hard in the college. • Studying hard, you will pass the exam.
• He seems to know this. • I hope to see you again.
• 进行时：表示正在发生的动作，与谓语动 词表示的动作同时发生；
• He seems to be eating something.
• 完成时：表示动作发生在谓语动词之前 • I am sorry to have given you so much trouble. • He seems to have caught a cold.
辨析：
• It is +adj of sb. To do sth • It is +adj for sb. To do sth
• It is nice___ you. • It is hard___ you.
• 用介词后面的代词作主语，介词之前的形容词 作表语，如果能组成句子就用of,否则就用for.
• 完成进行时：表示句子的主要谓语动词所 表示的动作发生时，不定式表示的动作正 在进行，不定式的动作从过去某个时段发 生一直持续到现在；
• She is known to have been working in our company for more than twenty years.
不定式的语态
3. 都有语态和时态的变化。如： He has finished his homework.（完成式）
Having finished his homework, he went out. The overpass will be built there.（被动）
The hospital being built will be completed next month.
注意
*1、动词不定式作主语时，谓语动词用 第三人称单数形式。例如
To get there by car takes a whole day.
To make a plan for our future is important.
• It 做形式主语，不定式作逻辑主语时一般有 介词for, of等引导；
（2） 作宾语 Would you like to watch TV?
不定式作宾语的动词常见的有：want, hope, wish, ask, choose, decide, manage, offer, promise, refuse, seek, pretend, learn, afford, need…
• 作主语 • 作宾语 • 做补语 • 做表语 • 做定语 • 做状语
不定式的语法功能
（1） 作主语
To talk with him is a great pleasure.
一般情况下，不定式（短语） 作主语时， 通 常用形式主语“it” 代替
It is a great pleasure to talk with him.
不定式的否定形式
• 动词不定时的否定形式是在不定式符号前 加not
• The teacher warned the students not to cheat in the examinations.
• She pretended not to see me when I passed by.
不定式的基本用法：
• It is easy for me to do that.
• It is very hard for him to study two languages.
• 当用it is +adj+ of sb. To do sth 一般表示人 物的品行和行为特征，it’s 后面多用表示主 观情感和态度的形容词；