<![CDATA[This study examines the lexical similarities and differences between older and younger Kayan speakers in Sungai Asap, Belaga, Sarawak. The study pursues two primary objectives: (i) to compare the extent of lexical retention and lexical variation in the basic vocabulary used by older and younger Kayan speakers based on Morris Swadesh's 200-word word list; and (ii) to identify the social factors influencing lexical change across generations. A qualitative descriptive research design was employed, supported by lexicostatistical analysis. Linguistic data were collected through structured interviews with native Kayan speakers representing two generational groups and were analysed using Swadesh's Lexicostatistical Theory (1952) alongside Fishman's Theory of Language Maintenance and Language Shift (1991). The findings indicate that a substantial proportion of the traditional Kayan basic vocabulary has been retained across generations, reflecting the continued vitality of the language within the community. Nevertheless, lexical differences were identified among younger speakers, particularly through lexical replacement, borrowing from Standard Malay, Sarawak Malay, and Iban, as well as minor phonological variation. The study further reveals that multilingual interaction, formal education, interethnic communication, and socioeconomic mobility are the principal social factors contributing to lexical change. Despite these influences, the Kayan language remains actively maintained within family and community domains, demonstrating a strong level of linguistic resilience and cultural continuity. The findings contribute to the documentation of indigenous languages in Sarawak and provide empirical evidence supporting ongoing language maintenance and revitalisation initiatives. Keywords: Kayan language; lexical comparison; language maintenance; lexical change; Swadesh List; sociolinguistics; indigenous languages; Sarawak]]>
