EN
The article discusses the active role of language in the perception of reality and development of cognitive processes, from von Humboldt’s thesis to the assumptions of cognitive linguistics to the methodology of the linguistic picture of the world and the concept of cognitive definition. The issues presented in the study concern the role of cognitive definition in the process of logopedic diagnosis. This type of definition provides insight into the store of knowledge that a subject (a studied person) has, enables showing differences between the child’s structure of concepts and the concepts used by adult language speakers. It illustrates the character of conceptual knowledge (e.g. the presence of only some categories in the conceptual structure) and the specificity of how words are defined (e.g. the poverty of. lexical devices) in the definitions formed by a person with an intellectual disability. The features of a cognitive definition are presented by means of polar antonyms, such as: beauty – ugliness, love – hate.