can someone correct my grammar, and help me give a better conclusion?

Piaget's theory of cognitive development is a theory about the nature and development of human intelligence. Piaget theory was first developed by Swiss developmental psychologist Jean Piaget.

Jean Piaget was born in Switzerland in 1896. After receiving his doctoral degree at age 22, Piaget began a career in psychology and education. After working with Alfred Binet, Piaget developed an interest in child intellectual development. He had observed children for a while, and his observations concluded that children were not less intelligent than their adult counter parts; they just think differently.

“According to psychologist Jean Piaget, children development progress through a series of four key stages of cognitive development marked how they understand the world”. The four stages of Piaget's theory of cognitive development is Sensorimotor, Preoperational, Concrete operational, and Formal operational.

The first stage of development is called the sensorimotor stage, which takes place from birth through ages 18-24 months. This stage is centered on infants trying to make sense of the world. During the sensorimotor stage, an infant's knowledge of their surrounding is limited, also his or her sensory perceptions and motor activities. Their Behaviors is limited to simple motor responses caused by sensory stimuli. With the natural born skills Children utilize the skills and abilities they were born with (such as looking, sucking, grasping, and listening) to learn more about the environment.

Stage two, is the Preoperational stage, which takes place between the ages two and seven. Through this stage, children language skills start to be developed. When children begin to learn language skills they mimic, manipulate information they learned from others.

Stage three, Concrete operational is a stage that begins around age seven thru age eleven. During this time, children began to gain a better understanding of mental operations, which they begin thinking logically.

Stage four, is the formal operational stage is the fourth and final stage of Piaget's theory of cognitive development.The formal operational stage begins at the age twelve and lasts into adulthood. During stage, people develop the ability to think about abstract concepts, and Skills, such as logical thought, deductive reasoning, and systematic planning.

In conclusion, The Piaget stages of development theory are a blueprint that describes the various stages of normal intellectual development, from infancy through adulthood. These stages include thought, judgment, and knowledge gained each stage.