情态动词can的用法

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,情态动词,can,的用法,简介,用法,练习题,简介,Can+,动词原形 没有人称和数的变化,否定形式,cannot/cant,，,cannot,比缩略形式,cant,要正式，口语中一般用缩略形式。,例如：,I can swim.,Daming can ride a bike.He cant drive a car.,用法（一）,表示能力（体力、知识、技能等），此时可用,be able to,代替。,例如：玛丽会说三种语言。,Mary can speak three languages.,=Mary is able to speak three languages.,注意事项,注意（,1,）：,can,只有一般现在时和一般过去,式；而,be able to,则有更多的时态。,例如：,Ill be able to come this afternoon.,今天下午我将会来。,注意（,2,）：,当表示“经过努力才得以做成功某,事,”,时应用,be able to,，不能用,can,。,例如：,He was able to go to the party yesterday,evening in spite of the heavy rain.,尽管下很大雨，他昨天还是能来参加聚会。,用法（二）,表示请求和允许,例如：,-Can I go now?,-Yes,you can./No,you cannot/cant.,此时可与,may,互换。在疑问句中还可用,could,might,（不可用于肯定句、否定句或答语）代替，不是过去式，只是语气更委婉。,例如：,-Could I come to see you tomorrow?,-Yes,you can.(No,Im afraid not.),用法（三）,表示可能性猜测,例如：,The man over there cant be my uncle.,My uncle has gone to Beijing.,那个人不可能是我的叔叔。,我的叔叔去北京了。,练习题,()1.My brother cant sing but he _ play the piano.,A.cant B.doesnt C.can D.dont,()2.-Why do you think the man is running?,-He _ be _ for exercise because,he is wearing a suit.,A.,must,running B.cant;run,C.cant;running D.could;running,用法一,用法三,总结,can+do,can,用法有三：,表示能力,表示请求和允许,表示可能性猜测,THANK YOU VERY MUCH,！,