Muttersprache

Muttersprache, literally "mother tongue" in German, is a term used to describe the language a person first learns and uses in everyday life. In many definitions it corresponds to the speaker's native language or first language (L1), typically acquired during early childhood through family and social interaction. In linguistics the term is sometimes used interchangeably with Erstsprache, though exact usage varies by field and region.

Acquisition usually begins in infancy and proceeds through natural exposure and practice within the home and community. A Muttersprache commonly shapes pronunciation, vocabulary, and basic syntax, and it can influence later language development. In multilingual contexts a person may have more than one Muttersprache or an L1 that remains dominant in certain domains.

Social and cultural aspects are linked to Muttersprache. It is often tied to identity, heritage, and community belonging, and it affects schooling, literacy, and participation in social networks. Surveys and policies sometimes collect data on Muttersprache to understand language needs and to support language maintenance and education in immigrant or minority populations. Language shift can occur when another language becomes more dominant at home or in public life.

Muttersprache vs other terms: while commonly equated with L1 or Erstesprache, the term is not universally fixed. Some scholars reserve Muttersprache for the language of the mother, others use it more broadly for the language learned in childhood. It is distinct from Zweitsprache (second language) and Fremdsprache (foreign language), which are typically learned later and used in different contexts.