Sensorymotor-0-2. develop object permanance Preoperational-2-5 Language development,using symbols,Role playing,Egocentrism,NO Conservation Concrete 7-11During this time, children gain a better understanding of mental operations. Children begin thinking logically about concrete events, but have difficulty understanding abstract or hypothetical concepts. Use inductive logic-going from specific event to larger.Reversibility Formal 12-adult think about abstract concepts. Skills such as logical thought, deductive reasoning, and systematic planning also emerge during this stage. (concrete) objects are no longer required and mental operations can be undertaken ’in the head’ using abstract term