Language shift, code-switching, and linguistic change in a contested borderland: A Japanese-Korean-Russian multilingual community in Sakhalin

Objectives: This study investigates language shift, code-switching, and linguistic change in an understudied trilingual Japanese-Korean-Russian speech community on Sakhalin. It elucidates how successive political regimes, demographic transformations, language/dialect structure, and speaker proficiency shape diglossic relations, language choice patterns, and multilingual practices. Methodology: Using implicational scales, macro-level analysis visualizes language choice across interlocutors and domains. Micro-level analysis draws on Myers-Scotton’s Matrix Language Frame model and Poplack’s code-switching typology, with apparent-time analysis to identify linguistic innovation and change. Data and analysis: Five hours of recordings from 16 second-to-fourth-generation Sakhaliners of Japanese, Korean, and mixed heritage yielded 220 multilingual utterances and 450 code-switching instances, analyzed alongside self-reports on language choice. Findings: Macro-level analysis reveals a typical three-generation language shift pattern for Koreans but not Japanese, demonstrating that changes in demographics and institutional support can produce abrupt language shifts. Diglossia exhibits initial structural stability but eventual instability: high languages are replaced by successive colonial powers, while low languages persist through the third generation before facilitating language shift. Micro-level analysis confirms the applicability of both Myers-Scotton’s and Poplack’s frameworks across typologically similar (Japanese/Korean) and dissimilar (Russian/Japanese, Russian/Korean) language pairs. Code-switching functions—quotational authenticity effects, audience inclusion, compensatory/emphatic purposes, and identity marking—enhance communicative efficiency. Apparent-time analysis identifies three age-cohort-specific speaker innovations (analogical leveling, light verb formations, novel negation constructions) and one change in progress: the productive Russian tag question construction, appearing across age cohorts. These patterns demonstrate a systematic preference for regularity and invariant forms in language change. Originality and significance: Providing rare systematic linguistic documentation of a historically stratified language contact zone, the findings advance theoretical understandings of diglossia, language shift, code-switching, and contact-induced innovation and change. They highlight preference for regularity , predictability , and communicative efficiency and underscore the importance of considering language/dialect structure, speaker proficiency, and sociohistorical context in multilingual analysis.