Well, you're not supposed to use it. At last that's what I was taught in school...that it is not correct English grammar. It is still commonly used as slang. When people do use it, they use it to replace "am not" or "is not". Here are some examples: - I ain't going to eat that! - That ain't the right way to throw a baseball. - The Chicago Bears ain't going to win the Superbowl. The grammatically correct versions would be: - I'm not going to eat that! - That isn't the right way to throw a baseball. - The Chicago Bears aren't going to win the Superbowl. I hope this helps!

"Ain't" is controversial. All dictionaries and all teachers say that it is unacceptable, and "ignorant." I would strongly advise you not to use it... even though you WILL hear it all the time, and you WILL hear it from educated speakers. It created a firestorm in the 1960s when Webster's Third New International Dictionary included it, even though the definition clearly identified it as nonstandard. "Ain't" can mean: "Am not:" "I ain't sayin' you treated me unkind/You could have done better, but I don't mind"--Bob Dylan song. "Are not:" "Those peaches ain't ripe yet." (I just made that one up, and it would probably sound more realistic if I said "Them peaches ain't ripe yet.") "Is not:" "It ain't the 'eavy 'untin wot 'urts the 'orses 'oof, its the 'ammer, 'ammer, 'ammer on the 'ard 'igh road." (Famous joke from Punch, illustrating supposed British Cockney usage). "Have not:" "I ain't got nobody/And nobody cares for me." (1930s song). The terrible thing is that in English we don't have any short contraction for "I am not." "Amn't" doesn't exist. And "ain't" is so stigmatized that we can't use it.

Ain't is pretty much "Isn't" "Are not" you can use ot in a lot of ways but it is pretty much slang. For example "This ain't right" would be like saying "This isn't right" Another example "This ain't worth my time" would be like saying "This isn't worth my time" However it is definitely not proper to say "ain't" so unless you're with friends you ain't gonna be using it much!

ain't is very informal = not got / have not i ain't got any money = i have not got any money