Piaget's stages of cognitive development include the sensorimotor stage from birth to 2 years, the preoperational stage from 2 to 7 years, the concrete operational stage from 7 to 11 years, and the formal operational stage from 11 to 16 years. According to Piaget's theory of cognitive development, the transition from concrete to abstract thinking that occurs around age 11 represents the critical period for second language acquisition. Piaget also described the concepts of equilibration, states of disequilibrium and uncertainty resolving into equilibrium and certainty, as key factors in cognitive development alongside maturation, physical environment, and social interaction. The document contrasts rote learning based on repetition versus meaningful learning through understanding relationships between facts. Finally, it