英语中如何将肯定句变成否定句?肯定句变成疑问句?

见以下,很简单.


一.肯定句变成否定句 
如果句中有be动词is,am,are 或情态动词must,can等,在其后面直接加not,
  she is your mother.     she isn't your mother  

   2.如果没有be动词或情态动词,加don't,does't或did't
         she likes playing football.   she doesn't like playing football.


二.肯定句变成疑问句
    变成一般疑问句

如果有be或情态动词动词就把他们提前,
      she is your mother.    Is she your mother?

   2.如果没有就在前面加do的某种形式,第三人称用does,过去时用did
      she likes playing football.       Does she like playing football?

   变成特殊疑问句,
       要具体分析,看是对什么进行提问,简单来说,
      1.对人提问用who, she is your sister.Who is your sister?
      2.对事物用what,     The book is on the desk.  what it is  on the desk?
      3对时间用when,     She will come back tomorrow. When she will come back?
      4.对频率用how often等等   I  play  football everyday. How often does you play  footall?


基本就这些了,