"Ain't" isn't used in standard English, so you wouldn't want to use it in a business or academic environment. "Amn't" doesn't exist. All the others are grammatically correct. But in speech, you would want to use the contraction "I'm" rather than "I am." Also, "am I not" sounds somewhat formal, and "Am not I" sounds extremely formal and dated. For a more informal tone, I would suggest, "I'm a teacher, right?"

"I am not a teacher, am I?" sounds like someone is asking for confirmation that they are not a teacher (and they would be surprised or maybe upset if they were). amn't I actually does exist in some dialects of Scottish and Irish English, in questions only--I had to look this up though since I haven't heard it where I live. There is also an't (as opposed to ain't) in some dialects of Black English. Everything else said by Jonathan Kimball and Lizzy B. I agree with. I would say "I'm a teacher, aren't I" in my dialect of English (White Canadian).

Hey Maksim! 1. You are correct - 'ain't I' is extremely informal (and regional). We would never use it in writing, and most English speakers don't even use it in speaking. 2. 'Am I not' is correct, 'Am not I' is never correct. This is because to turn the statement 'I am not' into a question, the only thing we need to do is flip the subject ('I') and the verb ('am'). Therefore, 'not' doesn't change its position. 'Am I not' isn't arrogant per se, but is often used in a rhetorical sense. For example, if someone says 'I am a teacher, am I not?', what they really mean is, 'Obviously I am a teacher!' 3. 'Amn't I' doesn't exist. As you have noticed, it looks (and sounds) very strange, and English speakers agree! This is why we choose to say 'aren't I' instead, because it is much easier to pronounce and looks nicer written.