Dysphasia is a verbal communication disorder. It appears from an early age with an absence of language and the development of a simplified language and a limited lexical field. It can affect expression, understanding, or both functions simultaneously. Verbal production is often poorly structured, vocabulary is poor, instructions are not understood. Dysphasia causes problems at school and is often very debilitating in social life. It is differentiated from aphasia, which is a verbal communication disorder (expression and understanding) that appears suddenly, when its functions were acquired and normal before.