'Ain't' is commonly used to replace "am not", "is not", "are not", "has not", "have not" , "do not", "does not", and "did not". Common examples: A: You're lying to me, aren't you? B: No, I ain't! (No, I'm not!) We ain't going to her party because she's a snob. (We aren't going to...) They ain't very nice people. (They aren't...) I ain't seen you in ages! (I haven't seen you in a long time.) A: Would you loan me ten dollars? B: I ain't got any/no money. (I don't have any....) <----used with 'no' it becomes a double-negative but is quite commonly used in this manner A: I need a cigarette! Do you have any/one? B: Nope. I ain't got any/none. (I don't have any...) <----used with none becomes a double negative Although ain't is no longer considered slang, it is still not considered "proper English" by many, and some even refer to it as 'low English'. Most definitely it is seen as informal speech in both the UK and US. I grew up in Texas in the US, so ain't and y'all are both quite commonly used, especially among the working class and those who live in rural areas. I use both as part of my everyday speech with friends or family, but I definitely would not use 'ain't' in a professional environment because of the stigma tied to its use. I would advise that you not use ain't as part of your speech. There isn't really any practical use for it.

'Ain't' is an abbreviation for is not/has not/and similar things, it used to just be slang, however now it's part of the English dictionary. 'Ain't nobody got time for that' is incorrect English, with a double negative,which is from a news interview with an Oklahoma resident called Kimberly Wilkins, which has been turned into an internet meme.

"ain't" word is a slang word. Its an improper word. so if your talking to a friend or simply an ordinary day you can use the word ain't. but If your talking to someone in a proper occasion, like interview or business meeting its not proper to use it. hope it helps cheers!