' Ain't ' is a slang word used all across the United States, though it was originally just used in Southern US English. It spread because it's a highly-useful word. Basically, it wraps up the whole "be not" construction into a single package. For example: I ain't we ain't You ain't they ain't He ain't y'all ain't In present and future tense, you can replace any 'be not' phrase with 'ain't': He ain't going to school tomorrow. They ain't American. That said, I'm from the Southern United States, and I refuse to use this word even when I speak. I despise it. I won't tell you to avoid it, though. Most people have no problem with the word in America. As for 'won't', it's a replacement for 'will not'. Most people believe it's a contraction of 'will not', but it's actually from Old English and comes from a different contraction than 'will not'.

It's used in some dialects as an informal way to negate almost anything. In addition to what Pornpimon mentioned, I've heard it used to mean "are not" and "have/has not". I don't think I've ever heard it used to negate "does not". In archaic English it was apparently a negation of "am not", but it's not standard English nowadays. It's apparently a part of everyday speech in some dialects in the southern US and remote parts of England, but otherwise people often think people that use "ain't" are uneducated and/or associate them with the rap or hip-hop sub-cultures. I wouldn't think much of it if someone who has an obviously southern US accent said it, but if I heard someone who clearly wasn't a native speaker of English say it I'd probably think they're trying to associate themselves with people like Kanye or 50-Cent. I'd only recommend you use it if you're in a place where you know it's used.

"Ain't" is a slang term and is a substitute for:  "is not" ("That ain't right!")  "am not" ("I ain't doing that!")  "will not" ("I ain't doing that either!")  and so on.  It's slang term Source : https://answers.yahoo.com/question/index?qid=20110224060641AAjR6kd

"Ain't" ain't a word, "ain't" ain't! ( "Ain't" isn't a word, "ain't" isn't!) You may hear ain't, but you should never use it in written English. It is only ever spoken, it also makes you sound uneducated when you use it. It means "is not" or "am not". "Won't" is perfectly acceptable, written and spoken, it means "will not". Hopefully you won't use "ain't" again!

Here is a link to a Sheryl Crow song where you can here the use of "wanna" as in "All I wanna do". Wanna = "want to" http://www.italki.com/entry/471271