My four year old son has become more and more difficult as every day passes. He does not seem to comprehend what he is told. When I ask him why he has done something and ask him if he understands, he says no. He is told right from wrong on a daily basis and does not seem to either remember or chooses not to obey. He is an intelligent child. Knows his colors and has recently learned how to spell some of them. We can yell, spank, take away toys, put him in the corner, make him take time outs, and any other type of dicipline, but he does not seem to get it. He is doing the same things later that day. I am so frustrated with him and I cannot take it anymore. He is always in trouble and I am tired of having to discipline him all the time. It seems as if he just cant understand what his father and I tell him. I do not know what to do with him and I think there may be something medically wrong with him. I am asking for your medical advice and help. I cannot take this anymore. I know that he is only four, but he just seems to be behind the other kids his age. Please help me figure out what is wrong with him and what I can do to help him and to help us. I have looked on the net for ways to diagnose what he may have and have had no luck. Again please help me.