当陈述部分是I am形式时,简略问句一定要用aren't I 那么 am I 什么用法呢

当陈述部分是I am形式时,简略问句一定要用aren't I
而且要记住,就算前面是I am not 开头
后面也要用aren't
比如：I am as tall as your sister,aren’t 我跟你姐姐一样高,对吗?
换言之,若前面是否定陈述：
I am not as tall as your sister,aren’t 我跟你姐姐不一样高,对吗?
am I 的用法如:
Am I a student?
But am I still the one?
Am I that easy to forget?

没有aren't I的说法。用法：我能吗？