What is a Language Disorder?
Like speech, language develops according to a timetable and in response to cognitive development. Some researchers would even say that language plays a role in shaping cognition. When an object is named, for example, the thinking process about that object is changed to include the attributes of the object that the child has experienced, i.e., shape, structure, taste, smell, color, etc. As the child develops a vocabulary, these words with their underlying meanings are then combined to create utterances according to rules of syntax and grammar. While the child is learning the vocabulary, syntax and grammar of her language, she is also learning the social customs regarding its use. These are internalized as pragmatic rules.
Children whose language development lags significantly from the developmental timetable may be considered developmentally delayed in language acquisition. A child with a language disorder may not use the language commensurate with her peers. She may be delayed in acquiring the vocabulary, syntax, grammar and pragmatics of her age mates. The child may have some of the characteristics of the language expected for her age, say vocabulary, but may be behind in syntax. Another child may have difficulty understanding the pragmatics of language and not know what to say in a given situation, whereas vocabulary may be limited in yet another. These problems in language development may be correlated with problems in later developing language-related areas such as reading.
Language skills develop at different rates in all children. See Speech and Language Checklist.