********** NOT A TEACHER **********
Hello, Priyaradha.
If you must choose only one answer, then I guess it would
be am I not. Everyone agrees that this is correct English.
In real life, however, most native speakers would probably
say aren't I because it takes too long to say am I not, and
because it sounds so formal. Most teachers would tell you
to avoid ain't because many (not all!!!) people use ain't only
when they want to be humorous or funny.
Thank you
I'm afraid I have to disagree. I have seen your recent comments about the use of contractions so I can see why you would not automatically choose "aren't I?", but these days, contractions are taught as an integral part of English.
The two academies I have worked for in Spain (as well as the biggest and most respected English teaching system in Spain) insist that when a student constructs a sentence, they use contractions wherever possible.
Teacher: Where have you been on holiday?
Student: I have been to Italy.
Teacher: Good, but instead of "I have", what could you say?
Student: Ah yes, of course. I've been to Italy.
Teacher: Great. OK, next question!
I don't think we use "aren't I" instead of "am I not" because it's faster, just because it's now natural, regular English.
I also don't think "ain't" is used to be humorous/funny. I personally agree that it's poor English and I don't use it, but it's not used for amusement value, it's simply how some people choose to speak.