What ain't and attaboy means in english

 Both are informal English expressions:

“ain’t”

• A nonstandard contraction often used in casual speech.
• It can mean “am not,” “is not,” “are not,” “has not,” or “have not.”
• Examples:
  • I ain’t going → I am not going
  • She ain’t here → She is not here
• It’s common in conversation, but usually avoided in formal writing.

“attaboy” (or “atta boy”)

• An informal phrase meaning “good job!” or “well done!”
• Used to praise or encourage someone.
• Example: You finished the project on time—attaboy!