小学英语语法总结:情态动词

  小学英语语法总结:情态动词

  1)情态动词can(能够),must(必须),may(可以)

  结构:主语+can/must/may+动词原型

  He can make the tea.

  Sally can air the room.

  We can speak English.

  ★变疑问句将情态动词移到句首

  Can he make the tea?

  Can Sally air the room?

  Can we speak English?

  ★变否定句在情态动词后面加not

  He cannot make the tea.

  Sally cannot air the room.

  We cannot speak English.

  ★肯定回答及否定回答

  Yes, he can. / No, he cannot.

  Yes, she can. / No, she cannot.

  Yes, we can. / No, we cannot.

  ★特殊疑问句:(必背)

  What can you do?

  注意:情态动词的句子没有第三人称单数的变化,不要在情态动词或动词后面加s。

  2)must/have to的区别

  must 表示必须,是主观上觉得应该做,have to是不得不,是由于客观条件逼迫的必要要做

  must 只能用在表示现在和将来的句子里,而have to do可以用在任何时态

  3)must, may, might表示猜测:

  · must do 表示对现在事实的猜测

  · must have done表示对过去事实的猜测

  · must have been doing 表示对过去正在进行的事实的猜测

  · may/might do, may/might have done表示没有任何事实依据的猜测,might的可能性更小。

  4)can't/couldn't 表示不可能