动词不定式的时态上可分为三种,即:一般式to do,to be done;进行式to be doing;完成式to have done,to have been done;完成进行式to have been doing。下面小牛英语带大家学习不定式的完成体。
  
  一、动词不定式的完成体
  
  (1)如果不定式表示的动作是瞬间动作时,它表示一个在现在或过去某时之前已经完成的动作;如果是延续性动词,它表示一个一直持续到现在或过去某时的动作。

  A.常见的可接不定式的完成体的有:happen,see,appear,prove,pretend,seem等。例如:

  They seem to have experienced a destructive earthquake.
  他们似乎已经历了一场毁灭性的地震。(表示事情已经发生)

  My grandmother appeared to have lived a happy life.
  我奶奶似乎一直过得很幸福。(她的幸福生活一直持续到现在)

  B.常见的可用于“主语 + be said + to have done/been”,相当于主动句“People say that ...”,类似的结构有:be reported /thought/supposed/expected/believed/considered/known等。例如:

  Her husband is said to have given up smoking.
  据说她丈夫已经戒烟了。(戒烟发生在“据说”之前)

  The young girl is reported to have served the club for five years.
  据说那个小姑娘已经在这个俱乐部服役五年了。(不定式表示谓语动作所处的状态)

  C.常见的可以接不定式完成体的形容词有:glad,happy,sad,disappointed,satisfied,sorry,surprised等。例如:
  I’m sorry to have given you so much trouble.
  对不起,给您添了那么多的麻烦。

  We are disappointed to have known that our team lost the game.
  知道了我们队输了这场比赛,我们很失望。

  试比较下面不定式的一般式和完成式的区别:

  I’m happy to have seen you.见到你很高兴。(分手时说的话)

  I’m happy to see you.见到你很高兴。 (见面时说的话)

  I’m sorry to keep you waiting for a moment.对不起,要请你等一会。(说话时还未等)

  I’m sorry to have kept you waiting for a long time.对不起,让你等久了。(说话时已经等了很久了)

  (2)be + 不定式完成时态表示本该做或想做但又未做的动作。例如:

  You were to have arrived there early that day.
  那天你们应该早点儿到那。(但你们晚到了。)
  I was to have helped him then,but I was too busy.那时我本想帮他的忙,可我太忙了。(未帮他的忙)
  (3)表示“意图,打算”之意的动词如hope,wish,expect,think,suppose,want,plan,agree,mean,try等用过去时,后接不定时完成时做宾语时,表示想做而未做成的事情。这种意义也可用这类词的“过去完成时 + 不定式的一般式”来表达。例如:
  We wished to have put out the fire in thirty minutes.(= We had wished to put out the fire in thirty minutes.) 我们本打算半小时就把火扑灭的。(结果没有)
  The engineers planned to have removed the temple before the dam was completed.(=The engineers had planned to remove the temple before the dam was completed.) 工程师们决定大坝建成之前把那座寺庙移走。
  
  二、动词不定式的完成进行体

  
  动词不定式的完成进行体表示不定式的动作发生在谓语动词之前,并一直在进行着。其结构与不定式的完成体类似。如:

  He is said to have been translating Lu Xun’s works into English.
  据说他一直在把鲁迅的作品译成英文。(现仍然在译)

  He seems to have been teaching in that school for ten years.
  他似乎已经在那所学校教了十年书了。(强调继续教)

  The kind-hearted millionaire is very happy to have been helping the disabled.
  那位善良的富翁一直在帮助残疾人,并为此感到非常高兴。(仍在帮助)

  We supposed to have been living here till our children grew up.
  我们原以为可以在这一直呆下去,直到我们的孩子长大。(但我们家搬了)
  
  三、动词不定时完成体的被动式
  
  当主语与不定式的动词有被动关系,且不定式所表示的动作又先于谓语动词动作发生时,动词不定式就要用完成体的被动式。例如:

  The book is said to have been translated into many languages.
  据说那本书已被译成了多种语言。

  The oranges were thought to have all been sold out.
  人们认为桔子已经全部卖光了。

  He is very sad to have lost four relatives in the earthquake.  
  他为这次地震中失去了四位亲人而感到十分痛心。