have 用法分为实意动词和助动词.当助动词时是表示现在完成时,变反意疑问句时陈述句为否定,短小的疑问句用haven't;陈述句为肯定,短小的疑问句用have.当为实意动词时,变反意疑问句时陈述句为否定短小的疑问句用do;陈述句为肯定,短小的疑问句用don't.
is也分为实意动词和助动词,但不论为实意动词和助动词,变反意疑问句时陈述句为否定,短小的疑问句用is；陈述句为肯定,短小的疑问句用isn't.
举个例子吧!
There is an apple on the table,isn't there?
She has an apple,doesn't she?
She has finished it,hasn't she?
尤其要注意一下have 的两个用法啊!