语法俱乐部第十二章笔记 不定式短语
- 不定式短语,就是 to + 原形动词 构成的短语
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不定式与助动词的共同点
- 后面都接原形动词,例如
- I will go.
- I want to go.
- 都有“不确定”的语气,例如
- He is right.
- He may be right.
- He seems to be right.
- to be right,也是个推测,不是事实叙述,这种不确定语气是不定式与助动词之间一个很重要的共同点,可以用来判断何时该用不定式
- 都要采用过去完成式来表达相对的过去时间
- 助动词与不定式本身都无法完整表达过去时间,例如
- It must be raining now.
- It may rain any minute now.
- It might even snow.
- 第1句的助动词must缺乏过去式的拼法,第二句是对未来的猜测,第三句也是,此处用might不是may的过去式,只是比较保留,比较没把握的猜测语气
- 如果早上起来,看到地上是湿湿的,于是可以说:
- It must have rained last night.
- 在猜测过去的事情时,助动词不论是must,may还是might,都只能够表示“语气强弱”的差别,无法表达过去式,助动词后面必须接原形动词,所以也不能用过去式,因此,在语气助动词后面只能用完成式来表示过去,也就是采用must have rained这种句型
- 从这点来看,不定式也是一样,例如:
- It seems to have rained last night.
- It must have rained last night.
- 助动词与不定式本身都无法完整表达过去时间,例如
- 所有主要的语气助动词,都可以改写为不定式
- must -> have to
- will/would -> be going to, be willing to
- should -> ought to
- can/could -> be able to
- may/might -> be likely to, be allowed to
- 后面都接原形动词,例如
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不定式短语的词类,所谓“不定式”,它的词类“不一定是什么词”,即可当名词,形容词,副词使用
- 名词,句子的主语,受词都是名词,补语也可以是名词,这些名词位置都可以放进不定式短语当名词使用
- 主语
- To hesitate now would be fatal.
- 这个句子的主语是不定词短语to hesitate,不定词带由不确定语气。可以用代名词it当主语,把真正的主语移到后面,
- -> It would be fatal to hesitate now.
- 受词
- I want to marry you.
- 不定式短语to marry you当动词want的受词使用,不定式在此的语气接近助动词will或going to,表示“将要”
- 如果是 S + V + O + C 句型,那么受词位置的不定式也经常用it暂代,真正的受词移到补语后面,例如:
- I found it hard to stay awake.
- S + V + C 句型
- His suggestion is to start as soon as possible.
- 介词后面的名词位置通常不适合放不定式短语,如果在介词后面遇到动词,通常会采用动名词的型态,例:
- They talked about moving to the south.
- 形容词
- 名词短语,不定式短语当形容词使用来修饰名词时,因为它是片语形态,不适合放在名词短语中,而应该放在名词短语后面做后位修饰,例
- I have two reports to write this week.
- to write 做形容词修饰 report
- 补语位置
- 主语补语,例如
- Everyone is to leave the building immediately.
- 受词补语,例如
- I want you to tell me the truth.
- 主语补语,例如
- 名词短语,不定式短语当形容词使用来修饰名词时,因为它是片语形态,不适合放在名词短语中,而应该放在名词短语后面做后位修饰,例
- 副词
- 修饰动词,例如
- I went online to find some answers.
- 修饰形容词,例如
- Your question is easy to answer.
- 修饰副词,例如
- Who will win the election is still too early to say.
- 修饰动词,例如
- 主语
- 名词,句子的主语,受词都是名词,补语也可以是名词,这些名词位置都可以放进不定式短语当名词使用
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不定式与动名词的区分
- 动名词:用来代表一个动作或者一件事情,它的-ing字尾类似现在分词,有时带有“持续”的暗示
- 不定式:不定式具有不确定的语气,句中如果采用不定式短语,往往可以用某一个助动词来解读
- 动名词与不定式皆可,意思相同(begin, prefer, like, love, hate)
- After supper, they began to watch (or watching) TV.
- to watch:表示将要,
- watching:表示开始一个动作或一件事情,而且是一件具有持续性的事情
- 如果加上语气助动词,成为would love, would like, would hate之类,那么将要的意思就变得比较明确,这时候就只能用不定式作为受词了,如
- I would love to come to your party.
- 只能用不定式(hope, expect, agree, decide, intend)
- I expect to see you again soon.
- 动词expect的意思是期望,具有浓厚的不确定意味
- 只能用动名词(dislike, avoid, enjoy, keep, practice)
- I dislike reading ebooks on the computer.
- dislike后面放的是一个活动或者一件事情,而且比较肯定
- 动名词与不定式皆可,意思不同(remember, forget, regret, stop)
- I forgot to put the food in the refrigerator; now it’s all spoiled.
- 动词forget后面接不定式,意思是忘记“该去做,要去做”,具有不确定的意味,表示这件事情尚未做,forget to do something的结果就是没做
- I forgot putting the food in the refrigerator, so I couldn’t find at anywhere.
- forget后面用动名词,意思是忘了“这个动作,这件事情”,动名词不具有不确定的意味,代表一件“做了”的事情,forget doing something的意思就是做了之后忘了有这回事
- I forgot to put the food in the refrigerator; now it’s all spoiled.
- 使役动词(例如make)和感官动词(例如heard)后面,只能接动词原形或动名词,不能用不定式这种不确定意味
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不定式to 与 介词to 的区分
- 不定式to:来自助动词,具有不确定意味,
- The lady agreed to come over and help with the cooking.
- 介词to:表示一种相对关系,to的意思是“对、朝向”
- The manager agreed to downsizing.
- 不定式to:来自助动词,具有不确定意味,