高中英语语法——虚拟语气

虚拟语气无论从考试还是实际生活来看都是一个重点和难点，掌握其用法能够大大加强大家对英语的理解和应用，从考试的角度来看也能帮助大家提高分数。

虚拟语气

• 用法
  • 简单句
    • 情态动词的过去式用于现在时态时，表示说话人的谦虚、客气、礼貌或委婉地语气，常用于日常回话中。
      • Eg
        • Would you be kind enough to show me the way to the post office?
        • It would be better for you not to stay up too late.
    • 表示祝愿
      • 常用"may + 动词原形"表示祝愿。此时may必须置于句首(多用于正式文体中)。
        • Eg
          • May good luck be yours!
          • May you be happy!
          • May you have a good time.
      • 用动词原形
        • Eg
          • Long live the people!
          • Have a good journey!
    • 表示强烈的愿望
      • Eg
        • God save me.
        • Heaven help us.
      • 注：该类型的虚拟语气谓语仅用动词原形，第三人称单数也不加"s"。
    • 表示命令
      • 用法
        • 命令虚拟语气只能用在第二人称(you), 而且通常省略主语(you)。
        • 在句尾通常加上感叹号"！"
        • 虚拟语气动词用一般现在时
        • 否定形式的命令语气，可用助动词do, 再加上not。
      • Eg
        • Work！
        • Be more alert!
        • Don't be afraid.
    • 习惯表达
      • Eg
        • You'd better set off now.
        • I'd rather not tell you the secret.
  • 从属复合句
    • 名词性从句
      • 主语从句
        • 在It is/was + adj./过去分词 + that...结构中，使用某些表示愿望、建议、请求、命令、可能、适当、较好、迫切、紧近、重要等形容词后的主语从句可用should + 动词原形或省略should直接用动词原形(美式英语)来表示虚拟语气。
          • Eg
            • It is necessary that we (should) have a walk now.
            • It is reqiured that nobody (should) smoke here.
        • 在It is/was + 名词 + that...结构中，常用虚拟语气表示建议、命令、请求、道歉、怀疑、惊奇等。
          • Eg
            • It is my proposal that he (should) be sent to study further abroad.
            • Their desirre was that a treaty (should) be signed.
        • 用词说明
          • 形容词
          • 过去分词
          • 名词
      • 宾语从句
        • 在动词wish后的宾语从句中的虚拟语气
          • • 对现在情况的虚拟(与现在的事实相反)
              • • 从句用过去式或过去进行时(时间上是同时的)。其句子结构为：宾语从句的谓语be和were/was，实义动词用过去式。
                • Eg
                  • I wish (that) I knew the answer to the question.
                  • I wish (that) I were a bird.
            • 对过去情况的虚拟(和过去的事实相反)
              • • 用wish表示对过去事情的遗憾。其句子结构为：宾语从句的谓语用过去完成时或would, could, might + 现在完成时。
                • Eg
                  • I wish (that) I hadn't wasted so much time.
                  • I wish (that) I could have slept longer this morning, but I had to get up and come to class.
            • 对将来情况的虚拟(表示将来的主观愿望)
              • • 从句动词would/should/could/might + 动词原形，用wish表达对将来时间的愿望。
                  • 注：主句和从句的主语不相同。
                • Eg
                  • I wish it would stop raining.
                  • I wish she would change her mind.
            • 特别注意
              • 如果将wish改为过去式wished,其后的that从句中俄东西形式不变。
                • Eg: I wished I hadn't spent so much money.
              • 如果that从句中用would，一般表示对现状不满或希望未来有所改变或请求。
                • Eg
                  • I wish he would answer my letter.
                  • I wish you would help me.
        • 在表示建议、命令、要求、忠告等动词的宾语从句要用虚拟语气
          • • 由于这类动词本身隐含说话者的主观意见，认为某事应该或不应该则呢么样。这类动词后面的that从句均以“should + 动词原形”表示虚拟语气，其中should常被省略。
            • 用词说明
              • 表示“要求”的ask, desire, request, demand, require, beg等
                • Eg: They requested that he (should) sing a song.
              • 表示“提议、劝告、建议”的propose, suggest, recommend, advise, vote等
                • Eg: The doctor suggested that he (should) try to lose his weight.
              • 表示“决定、命令”的decide, order等
                • Eg: The boy decided that he should not become a carpenter.
              • 表示“主张”的maintain, urge等
                • Eg: I urged that he (should) read his report carefully.
              • 表示“同意、坚持”的consent, insist等
                • Eg: He insisted that we (should) tell him the news.
                • 注：在insist后面的从句中，如果是坚持自己，用陈述语气；如果是坚持别人做什么用虚拟语气。
                  • Eg: She insists that she is right.
        • would rather, would sooner, had rather, would (just) as soon, would prefer之后的宾语从句中的虚拟语气。
          • • 用于表达主观愿望，谓语动词用过去式表示现在或者将来；用过去完成时表示与过去事实相反，表示“宁愿做什么”或“对过去做的事感到懊悔”。
            • Eg
              • I would rather he came tomorrow than today.
              • The soldier would sooner die than surrender.
              • To be frank, I'd rather you were not involved in the case.
              • I would just as soon you returned the book yesterday.
        • "had hoped"后面的宾语从句中的虚拟语气
          • • 用“had hoped”表示原来希望做到，而实际上未能实现的事，其宾语从句的谓语用“would + 动词原形”。
            • Eg
              • I had hoped that she would go to the U.S. and study there, but she said she liked to stay in China.
              • I had hoped I would be promoted.
      • 表语从句
      • 同位语从句
      • 当某些表示建议、请求、命令等主观意向的名词作主语时，其后的表语从句或同位语从句需用虚拟语气，其表达形式为“should + 动词原形”或“直接使用动词原形”。
        • • 常见名词
          • Eg
            • We are all for your proposal that the discussion be put off.
            • The advice is that we (should) leave at once.
            • I make a proposal that we (should) hold a meeting next week.
    • 状语从句
      • 方式状语从句
        • 在as is/though引导的方式状语从句中，从句后面的谓语
        • Eg
          • It seems as if it were spring already.
          • Why is the girl looking at me as though she had seen me before?
      • 原因状语从句
        • I'm sorry/surprised/disappointed/that等结构中的原因状语从句
        • Eg
          • I am sorry that this should have happened.
          • I am surprised that he should have done this.
      • 目的状语从句
        • 在以in order that, so that引导的目的状语从句中，谓语多用"could/may/might + 动词原形"； 在口语中常用“can/could + 动词原形”。
          • Eg
            • She took a taxi so that she could get there on time.
            • In oder that you may get the job, you may have to pass the exam.
        • 以lest, for fear that和in case引导的目的状语从句中，谓语动词多用“should + 动词原形”或“动词原形(多用于美式英语)。”
          • Eg
            • She look his umbrella with her lest it should rain.
            • He burne all the important documents for fear that they should fall into the enemy's hands.
            • He doesn't dare to leave the house in case he should be recognized.
      • 让步状语从句
        • 以even if/though引导的让步状语从句，主句和从句均用虚拟语气。
          • Eg
            • Even if the boss were here, I would say the same thing.
            • Even though it had been a snowny day, he would have gone to see his patient.
        • 当从句有though/although引导，主语也可用陈述语气。
          • Eg
            • Though the whole class should criticize him, she will still back him up.
            • Even if I hadn't helped you, you could have done it yourself. 
        • 主句用陈述语气，从句用动词原形，省去连接词，将动词置于句首；在if/whether引导的从句中，动词用原形。
          • Eg
            • The business of each day be it selling goods or shipping them, went quite smoothly.
            • All matter, whether it be solid, liquid or gaseous, has weight and takes up space.
              • All matter, be it solid, liquid or gaseous, has weight and takes up space.
          • 注： 在以上几个句子中，用的都是虚拟语气(第三人称不加-s或-es)。其中的倒装语序属于古英语虚拟语气，至今仍保存在若干固定的语句中。
      • 条件状语从句
        • if引导的条件状语从句
          • • 与现在事实相反
              • 从句
                • If + 主语 + 动词过去式(be动词用were)
              • 主句
                • 主语 + should/would/might/could + 动词原形
              • Eg
                • If had time, John would make a trip tp China to see the Great Wall.
                • If I were you, I would give up drinking immediately.
            • 与过去事实相反
              • 从句
                • If + 主语 + had + 过去分词
              • 主句
                • 主语 + should/would/might/could + had done
              • Eg
                • We would have dropped by if we had had time.
                • If I were not busy, I would have come.
                  • 虚拟式were也可表与过去事实相反。
            • 与将来事实相反
              • 从句
                • If + 主语 + 动词过去式
                • If + 主语 + were to + 动词原形
                • If + 主语 + should + 动词原形
              • 主句
                • 主语 + should/would/might/could + 动词原形
              • Eg
                • If I were to see her tomorrow, I would tell her the truth.
                • If you went there next time, you would see what I mean.
                • If you should lose, what would you do?
        • if only引导的条件状语从句
          • • 表示强烈的愿望或者遗憾(用过去时或过去完成时)
              • Eg
                • If only I had more money, I could buy a computer.
                • If only you hadn't tole him what I had said, everything would have been all right.
            • 用于感叹句中(用过去时或过去完成时)
              • Eg
                • If only he were here!
                • If only I had taken her advice!
    • 定义从句
      • 在It is (about/high) time (that)的定义从句中，表示早该做而未做的事，常含建议的意味。
      • Eg
        • It's about time you went to bed.
        • It is time that we ordered dinner.
• 基本结构
  • 动词原形
    • Eg
      • God bless you.
      • Long live the people.
    • 注：动词原形，用于一切人称和数。
  • 动词过去时
    • Eg
      • If you loved me, you wouldn't say that.
      • If I were in your shoes, I'd accept the terms.
    • 注：动词的过去式，用于一切人称和数，be的过去式用were。
  • had + 过去分词
    • Eg
      • If I hadn't had to study for the exam, I would have gone to your party.
      • If I had listened to you, I would have finished my assignment.
    • 注：had + 过去分词，用于一切人称和数。
  • should(第一人称)和would(第二、三人称) + 动词原形
    • Eg
      • If I were you, I should take his advice.
      • He said he would go if I went.
  • should(第一人称)和would(第二、三人称) + have + 过去分词
    • Eg
      • If they hadn't helped you, you would have done nothing.
      • You wouldn't have seen her if it hadn't been for him.
  • should + 动词原形
    • Eg
      • They suggested that we should meet at the station.
      • If you should see Celila, give her my best wishes.
    • 注：sould + 动词原形，用于一切人称和数。
  • should + have + 过去分词
    • Eg
      • It is strange that she should have done it.
      • I should have taken his advice.
    • 注：should + have + 过去分词，使用一切人称和数。
• 定义
  • 虚拟语气用来表示说话人的主观愿望、假想、怀疑、猜测、建议等含义，所表示的不一定是事实，可能与事实相反。