语法俱乐部第七章笔记 语气助动词

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  1. 主要的语气助动词有must,will,would,should,can,could,may,might这几个,另外还有ought to,have to,used to,need,dare,had better,would rahter,might as well,这些词配合原形动词构成动词短语,用来表现各式各样的语气或态度
  1. 语气助动词的两种用法
    • 一般用法,例:
      • We must be very careful.
      • 这种用法用来表达义务,意愿,责任,能力,许可等
    • 猜测用法,例:
      • John must be very careless.
      • 这种用来用来表达猜测
    • 主要语气助动词的一般用法
      • must 表达义务,非如此不可,缺乏时态变化,现在时间和过去时间一样,例:
        • We must all keep together.
        • He said we must all keep together.
      • will / would,表达愿意,决心,承诺,在一般用法中有时态的差别,例:
        • I will have my own way.
        • He said he would have his own way.
        • 如果是过去时间,要采用过去拼法的would,不过would也可也用在现在时间中,表示客气地询问,例:
        • Would you like a cup of coffee?
      • shall / should,shall通常只见于shall I,shall we这种以第一人称询问对方意愿的讲法中,也可以用在相当正式的语气表达谈话者强烈的决心,例如
        • The enemy shall not pass!
        • 除此之外,一般都只会用到should,不管是现在时间,还是过去时间,一般用法表达责任,义务,不这样做不对,例:
        • We should always be on time.
        • He said we should leave early, and we did.
      • can / could,表达有能力,有权力,具有时态的差别,例:
        • I can drink a dozen beers in an hour.
        • Last night there was something wrong with my stomach, and I could not even finish one beer.
        • could也可以用在现在时间,表现特别客气的语气,例:
        • Could you please help me with my homework?
      • may / might,表达准许,许可,有时态的差别,例:
        • You may go now.
        • He said we might go.
        • might也可以用在现在时间中,表达语气上的客气
        • Might I ask a big favor of you?
    • 一般用法的过去拼法配合完成式
      • 在主要语气助动词中,作过去拼法的有would,should,could,might这四个,如果后面配合动词完成式,通常表示:1,相对于过去时间,2,非事实语气,例:
      • 例1:I woud have left the country if I had known what was going to happen.
      • 以过去拼法的would配合完成式,表示是从前的事,而且事实上并没有离开
      • 例2:You should have attemed the meeting last week; Why didn’t you?
      • 例3:With a little help, I could have finished a lot sooner.
      • 例4:Under a more reasonable boss, I might have done a much better job.
    • 主要语气助动词的猜测用法
      • 用于猜测时,will/would,can/could,may/might,这三对已经完全没有表达时态的功能,只是用来表达语气的轻重,will/can/may用于比较有把握的猜测,would/could/might用于比较没把握的猜测,而且所有的语气助动词,不论过去拼法还是现在拼法,配合完成式使用,意思就是猜测过去
      • must
        • Listen! It must be raining hard outside.
        • It must have rained last night - the ground is still wet.
      • will
        • That will be George at the door, I except.
        • You will all have heard the news last night.
      • would
        • This seat would be mine, right?
        • That would have been the mailman just now, I found some new mails in the box.
      • should
        • We should be on the right track.
        • He should have left, his car is gone.
      • can
        • Where can he be at this hour?
        • Where can he have gone.
      • could
        • Of course, I could be wrong.
        • The police is here,something could have gone wrong.
      • may
        • Don’t go near that snake, it may be dangerous.
        • It may have been dangerous, but now it’s gone.
      • might
        • Bring a compass, you might get lost in the woods.
        • Check the answering machine. He might have left a message for you.
  2. 次要语气助动词
    1. ought to
      • I think you ought to apologize to him. 一般用法
      • He ought to be home now. 猜测用法
      • You ought not to have done that. 一般用法,过去非事实语气
    2. have to
      • You have to tell your father. 一般用法
      • That has to be the pizza man at the door. 猜测用法
    3. used to
      • He used to somke a pipe. 一般用法
      • Used he to smoke a pipe? / Did he used to smoke a pipe? 一般用法疑问句
      • He used not to smoke a pipe. / He didn’t used to smoke a pipe. 一般用法否定句
    4. need
      • I don’t think you need go. 一般用法
      • Need I remind you of the consequences? 一般用法疑问句
      • You needn’t do that. 一般用法否定句
    5. dare
      • I’m not sure I dare touch that snake.
    6. had better
      • I think we had better leave now.
    7. would rather
      • I would rather go abroad than study at a local graduate school.
      • 如果would rather后面有than,因为这个than是比较级的连接词,要求前后对称,所以前面有原形动词,后面就可以用原形动词和它对称
    8. might as well
      • We might as well walk, with so much traffic on the road.
      • 这个助动词没有疑问句的形态,它的否定句可以这样表示:
      • We might as well not drive at all.