Piaget was born in Switzerland. He was a student of biology, and also had keen interest in psychology and philosophy. His interest in the study of cognition evolved while working in a laboratory.Piagets views indicate that there is no knowledge that is pre-existing in the world such that it can be taught to a child. Nor does knowledge comes innately (on its own) to the child. Knowledge develops when she acts on the world. It helps in understanding how children construct knowledge.Piaget states that for the child's all-round intellectual development language is the most important aspect.According to him, children first create mental structures within the mind (schemas) and from these schemas, language development happens. Jean Piagets theory of language development suggests that children use both assimilation and accommodation to learn the language.Assimilation takes place when people try to understand something new by fitting it into what we already know. Accommodation occurs when a person must change existing schemes to respond to a new situation.Hence, it is clear that Piaget's theory on language development suggests that language is learnt through assimilation and accommodation.