My 21 months old always use his tongue and pushes his food out of his mouth.. Now I cook diff food for him everyday..he prefer bread.. is tis normal?

Perhaps you can mix your son's love of bread with other ingredients. Maybe when hidden or mixed in bread, your child will be more accepting of the other foods. You can battering the bread with egg and lightly sautee it with some oil or butter (like french toast) or you can make soup/porridge and dip the bread in before feeding it to your child. This way it's a win win situation -- baby gets the bread and you get to feed him other nutritious food.