Is it okay to use ain't in formal conversation?
I know ain't can be used for am not, is not, are not, have not, has not. So if I can use it in day-to-day life, it will be easier for me I guess.
No, it is not the ideal phrase for a formal conversation. Maybe in commercials, music etc. but not in formal usage between someone you don't know. I mean if you use it in a supermarket it is OK, but kind of weird during a job interview or when talking with a doctor or somebody who you want to show some respect. But I will use it in marketing, commercials, music and stuff of that sort.