I have no idea what to do


Hey ladies my son is 4 and he has been in this new stage in his life where he is saying the word stupid a lot he said it too me I talk to him about but it got out of control he started calling his teachers stupid yesterday I put him on time out the whole day no tv no phone no toys he was sitting down the whole time until bed time he said I'm sorry andnim won't do it again today,he says it to a different teacher and I talk to him When I tell him how bad it is and I even spanked him and he stuck his tounge out now I don't know where all of this is coming from I was a revel as a kid and I got beat and I'm afraid I don't have any real other parent to guis me yes his my only child any advice ladies would really help