It includes morphology and syntax, often complemented by phonetics, phonology, semantics, and pragmatics (Grammar, n.d.). Pragmatics is the study of the ability of natural language speakers to communicate more than that which is explicitly stated; it is the ability to understand another speaker's intended meaning is called pragmatic competence; and an utterance describing pragmatic function is described as metapragmatic (Pragmatics, n.d.).

The Role of Language Processing in Cognitive Psychology

Jean Piaget, the founder of cognitive development, was involved in a debate about the relationships between innate and acquired features of language, at the Centre Royaumont pour une Science de l'Homme, where he had a discussion about his opinion with the linguist Noam Chomsky as well as Hilary Putnam and Stephen Toulmin (McKinney, & Parker, 1999). Piaget discussed that his cognitive constructivism has two main parts: an "ages and stages" component which foretells what children can and cannot understand at different ages, and a theory of development that illustrates how children utilizes cognitive abilities his theory of cognitive development suggests that humans cannot be "given" information that they immediately understand and use; but as an alternative, humans must "construct" their own knowledge and build their knowledge through experience that enable them to make schemas or mental models in their heads that are changed, enlarged, and made more sophisticated through two complimentary processes: assimilation and accommodation (McKinney, & Parker, 1999).

Also according to Piaget, the preoperational stage, from 2 to 7 years old, Language is the big thing for the children are developing their ability to think symbolically and starts the use language; also at this age, the child's thinking is still very intuitive and very concrete; words become intriguing and fascinating to them however they tend to confuse words with the objects they represent;...

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http://en.wikipedia.org/wiki/Lexicon

McKinney, M.L. & Parker, S.T.(1999). Origins of intelligence: the evolution of cognitive development in monkeys, apes, and humans. Baltimore: Johns Hopkins University Press.

Phonetics. (n.d). Retrieved March 13, 2009, from Wikipedia:

http://en.wikipedia.org/wiki/Phonetics

Pragmatics. (n.d). Retrieved March 13, 2009, from Wikipedia:

http://en.wikipedia.org/wiki/Pragmatics

Semantics. (n.d). Retrieved March 13, 2009, from Wikipedia:

http://en.wikipedia.org/wiki/Semantics

Smith, L. (1993). Necessary knowledge: Piagetian perspectives on constructivism. Hove, UK: Lawrence Erlbaum.