Punishment for bad behavior will only make your child feel terrible about himself and prolong the difficulty by further shutting down his thinking. Think about what's going on in your child's life. If your whole family is weathering a trauma, your child may be trying to handle strong feelings on his own without adding to your burden. You may never know exactly what's at the root of his difficulty with school, but you don't need to know in order to help him. Your child may be able to tell you straight out what's bothering him, or you may have to set up certain conditions first.
Children talk to adults when they feel safe, loved, and close.
You can give your child that sense of contact either by playing with him vigorously and generously, or by listening to him without judgment or interruption. Your child may also be more willing to open up if you ask him a positive question first. You'll hear about what's hard at school, but you'll have bypassed the hopeless feelings that can make children reluctant to talk. Let your child fall apart. Children keep a lot inside but are always looking for ways to get their feelings out.