Re: question tag
I don't know the reason that I am not" is contracted as "I'm not" but not "I amn't" -- but for whatever the reason, there is no "I amn't" in most dialects of English.
Therefore, you can't do the inverse and say "Amn't I" for questions.
Aren't I good enough for you?
Aren't I the the best person for the job?
I'm going, aren't I?
If they think this is just too weird, they can say "am I not?" instead.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.