学而思语法系列：15.情态动词

本系列导图是学而思小初语法课（1-9年级）知识点的归纳总结，涵盖6*时态 1*被动语态，8大词性，5种句型，3种从句。树叶内容是课堂上老师指导的快速记忆方法。

情态动词

• can, could, may, might, shall, should, must, ought to, had better, need, dare + 动词原形
• 委婉军团
  • 客气
  • can/could
    • 能够，会
      • Can I help you? Could you do me a favor?
  • May/Might
    • 可以，可能 常与第一人称连用
      • May I sit here? May I come in?
    • 祝愿
      • May you be happy.
  • Will you please ... Would you ...
    • 你能...吗？
      • Will you please open the window? Would you tell me the way to the station?
    • 你想...吗？
      • Would you like to grab some coffee?
• 义务军团
  • 必须
  • must
    • 必须（主观，心甘情愿）
      • I like studying. I must finish the homework today.
  • have to
    • 不得不（客观，心不甘情不愿); 非情态动词，有时态变化
      • I am so sleepy. I have to finish the homework today. In order to pass the exam he has to stay up to prepare.
  • should ＜ ought to ＜ had better
    • 语气强弱
    • 最好...
      • You should have a rest. You ought to see a doctor. You had better have an operation.
    • 否定
      • should not, shouldn't
      • ought not to, oughtn't to
      • had better not
• 肯否不一
  • 问句的肯否回答不一样
  • may
    • May I smoke here? Yes, you may. No, you mustn't (禁止)/ can't.
  • must
    • Must I clean the toilet? Yes, you must. No, you needn't / don't have to(不必要).
  • need
    • 作情态动词，只能用于疑问/否定句
      • Need I finish all the homework in one day? Yes, you must. No, you needn't.
• 推断军团
  • • I'm not sure
    • + do 对现在/将来推测
      • You must be tired after walking three days. Please have a rest.
      • She may know the truth, but I'm not sure.
    • + have done 对过去推测
      • The streets are all dry. It can't have rained during the night.
      • I mailed the letter two days ago. She must have received it.
  • needn't have done
  • should have done
  • 无推测功能
    • 本不需要做(实质已经做过) You needn't have said that.
    • 本不应该做(实质有做) With so much work on hand, you shouldn't have gone to see the game last night.
    • 本应该做(实质没有做) He should have known that the police would never allow this sort of thing.
• 情实共存 need
  • 情态动词
    • needn't do 只能用于疑问/否定句
      • I needn't have a rest. Need I have a rest?
  • 实意动词
    • need + n.
      • I need a rest.
    • need to do
      • I need to have a rest.
    • need doing =need to be done 表被动
      • The clothes need washing. The clothes need to be washed.