12.31非谓语动词

非谓语动词是指在句子中不是谓语的动词，主要包括不定式、动词不定式等。希望对你学习英语有所帮助！

不定式

• 形式
  • 动词不定式
    • 一般式：to do
    • 一般被动式：to be done
    • 完成式：to have done
    • 被动完成式：to have been done
    • 进行式：to be doing
    • 完成进行式：to have been doing
• 用法
  • 不定式
    • 作主语，一般表示具体的或一次性的动作
      • e.g. To stop the work now seems impossible.
        • 与动名词比较，动名词作主语时更强调这个动作是一般或抽象的经常发生的动作。
      • 更多情况下用it作先行主语，避免头重脚轻
        • It + be +形容词+ 不定式，e.g. Is it easy to learn a foreign language?
        • It + 名词 + 不定式，e.g. It's an honor to meet you.
        • It + 动词（宾语）+不定式，e.g. It costs a lot to build this museum.
        • It + be +介词短语+不定式，e.g. It is against my will to help him.
    • 作宾语
      • 动词v. + 不定式，e.g. like to do, prefer to do, manage to do...
      • 动词v. + 名词/代词+不定式，e.g. I asked him to leave.
        • to be; to have done, to be doing.
      • 连接代词/副词+不定式，e.g. She doesn't know what to say/ where to go/ how to do/ when to begin/ which way to go/ whether to go left or right...
      • 先行词it作形式宾语，e.g.
      • 使役动词、感官动词后可以接不带to的动词不定式，e.g. I heard her enter the house. 但是变为被动语态时，to需要被补充回原位置，e.g. She was heard to enter the house.
        • 使役动词：make, let, have 感官动词：see. notice, look at, watch, observe, listen to, hear, feel, taste, smell, sound 帮助，help
    • 作定语
      • 修饰事情/东西，表示未发生的动作，且常常后置，e.g. I have a lot of things to do./ There are a lot of things to be done.
      • 修饰人，e.g. She was the first person to win this game.有时也有被动形式。
      • 名词+不定式，不定式修饰名词，一般可以理解为固定搭配。
    • 作状语
      • 修饰形容词，be + 表示情绪、状态、品质等的形容词 + 不定式，e.g. She was pleased to see him.
      • 表目的：We sleep together to keep warm. 表原因：We jump with joy to hear it. 表结果：What have I said to make you so angry?
      • 修饰整个句子(短语)，e.g. To be honest, To put it in another way... 固定搭配，e.g. so as to, enough to, too...to...
    • 作表语：①说明主语的具体内容，Her goal is to win the first prize. ②表示目的，The wall is to keep people out of the garden.