Kasutuslingi

Kasutuslingi is a term used in Estonian linguistics to describe the language as it is actually used by speakers in everyday communication. It encompasses informal speech and writing, regional varieties, slang, colloquial pronunciations, and orthographic practices that are common in daily use but often outside prescriptive norms. The concept also accounts for code-switching and loanwords that speakers incorporate into their speech.

In linguistic practice, kasutuslingi is described from a descriptive perspective rather than a prescriptive one. It is distinguished from the normative kirjakeel or standard language by focusing on observed usage in real contexts—spoken interaction, informal writing, and media moderation. Researchers typically rely on corpora, fieldwork, and sociolinguistic observation to map variation across age, region, social group, and register.

Etymology-wise, the word is a compound formed from kasutus (usage) and a productive linguistic suffix, reflecting its status as a category that designates language as it occurs in real use. Its exact historical usage varies across texts, but the concept has been increasingly prominent in modern Estonian sociolinguistics as scholars stress descriptive accounts of language in use.

Applications of the kasutuslingi concept include corpus-based studies of frequency and syntax in everyday speech, the analysis of regional and social variation, and informing language education and lexicography. It supports more realistic teaching materials and more responsive language policy by highlighting how language changes in practice.

See also: kirjakeel, standard language, sociolinguistics, corpus linguistics.