Identifying the Preoperational Stage in Cognitive Development

In the field of developmental psychology, cognitive development refers to the process by which individuals acquire and utilize knowledge as they grow. A key theorist in this area is Jean Piaget, who proposed a series of stages that children undergo in their cognitive development. At what stage do children typically begin to engage in symbolic play and learn to manipulate symbols as well as representational thought, enabling them to think about objects and events that are not present?