My son has picked up some abuses from kids in his school and casually uses them in conversations. Ive tried scolding him and trying to make him understand its not right but he continues. My wife and me are worried, how do I break this habit?

if he is very young and still in the formative years, tell him that this is not a good word and ask him to stop then. if your son is older, talk to him openly and tell him that these words are not respectful, and you don't like them being used in the family. instead of scolding, try speaking and explaining why.