2．用于虚拟语气中时，表示与过去事实相反。
  You must have caught the bus if you had got up earlier.  如果你早一点儿起床的话，你准能赶上那一班公共汽车了。（事实上没有赶上公共汽车）
  He must have won the game if he had been careful enough.如果他足够细心的话，他准能赢得比赛。.

  D．needn't have done
  用于对过去的责备，表示“没有必要做某事，可是做了”。
  The airport is close to us. You needn't have hurried there early.机场离这儿很近，你没必要早早地赶到那里。（可是你早早地到那儿了）
  He is still young. You needn't have sent him such an expensive present.他还小，你没必要送他这么昂贵的礼物。
  注意：
  如表示“过去不必做也没有做”之意，需用didn't need to do。
  It is not cold today. I didn't need to take the thick sweaters out.今天天气不冷，我没有必要把厚毛衣拿出来。（实际上也没拿）

  E．shouldought to have done

  1．表示对过去动作的责备或批评。
  You should have gone over your lessons. (In fact you didn't go over your lessons.)你们应把功课复习好的。（可事实上你们没有。）
  You shouldn't have watched TV last night. (In fact you watched TV last night.)你们昨天晚上本不该看电视。（可你们看了。）
  You oughtn't to have entered the teachers' office without permission.没有经过允许，你们本不该进老师的办公室。
  You oughtn't to have gone to the deserted place alone.  你不该独自去那荒凉之地。

  2．表示期待或推测。
  If the flight was on time, you should  ought to have arrived in Shanghai early this morning.如果航班准点的话，你今早就能到上海了。
  The building should  ought to have been completed by the end of the week.这幢建筑物本周末前应该能完工。

F．would have done

  表示与过去事实相反的假设或结果。
  I would have been happy to see him, but I didn't have time.我会很高兴和他见面的，但我没时间见他。
  If your father had still been alive, he would have felt very proud of you.你父亲如果还健在的话，他会为你骄傲的。

第五章  动词不定式（一）

  动词不定式是动词的一种非谓语形式，在句中不能单独作谓语。动词不定式具有动词的性质，它可以有自己的宾语和状语，从而构成动词不定式短语。它还可以有形式的变化，即一般式、进行式、完成式和被动式。同时，动词不定式也具有非动词的性质，相当于一个名词、形容词或副词，可以在句中担任主语、宾语、宾语补足语、表语、定语和状语。

一、动词不定式的特征和种类

  动词不定式是由不定式符号to+动词原形构成，在某些情况下to也可省略。

   A．不定式的一般式
  不定式的一般式表示的动作通常与主要谓语的动作同时或几乎同时发生，或是在它之后发生。
  He appears to be very happy.他看起来好像很高兴。（同时发生）
  To catch the train, we'd better hurry to the station by taxi.为了赶上火车，我们最好赶紧乘出租车去车站。（to catch the train发生在hurry to the station之后）

B．不定式的进行式
  不定式的进行式表示正在进行的或与谓语动词同时发生的动作。
  It happened to be raining when I got there.我到达那里的时候，天碰巧在下雨。
  I'm glad to be traveling with you.我很高兴和你一起旅游。

C．不定式的完成式
  不定式的完成式表示的动作在谓语表示的动作之前发生。
  I'm sorry to have lost your key.我很抱歉把你的钥匙弄丢了。
  I meant to have finished my work last night, but I didn't feel very well.我本来想昨晚完成工作的，但是我感觉身体不舒服。
  It has been an honor for me to have been invited to your country.对我来说，被邀请来你们国家是一件很荣幸的事情。

D．不定式的完成进行式
  不定式的完成进行式表示的动作在谓语之前发生并且一直进行着。
  He was said to have been living in London for twenty years.据说他在伦敦一直住了20年。
  I'm sorry to have been interrupting you.很抱歉，我一直打扰你。
  比较：
  不定式的时态意义。
  He is said to be studying abroad.据说他正在国外读书。（不定式的进行式表示动作正在进行）
  He is said to have studied abroad.据说他在国外学习过。（不定式的完成式表示动作已经结束）

E．不定式的被动形式
  当不定式逻辑上的主语是这个不定式表示的动作的承受者时，不定式一般要用被动形式。不定式的被动形式根据其与谓语动作发生的先后关系，有一般式和完成时两种。

  1．一般式to be done
  These are the books to be given out to the students.这些是要发给学生的书。
  He asked to be sent to the place where he was most needed.他要求被派往最需要他的地方。
  2．完成式to have been done
  The novel is said to have been translated into many languages.据说这部小说已被译成多种语言。
  He appeared to have been questioned for many times.看起来他已经被询问过很多次了。

  F.不定式的否定形式
  不定式的否定形式由not或never加不定式构成。
  We decided not to go out because of the bad weather.由于天气不好，我们决定不出去。
  Never to have made any mistake is impossible.从不犯错是不可能的。
  注意：谓语动词的否定和不定式的否定不同的意义
  I did not promise to wake him up.我没有答应叫醒他。
  I promised not to wake him up.我答应了不叫醒他。