Somsonge Burusphat2013-02-122013-02-121836-6821ISO 639-3 language codes: soa, blthttp://hdl.handle.net/1885/9719The research question of this paper is: To what extent has the Thai Song language been influenced by the Thai language? The finding of this question is obtained by a sociolinguistic study of phonological variation and lexical replacement among Thai Song speakers of three age groups: old generation (over 60), middle generation (35-55), and young generation (18-30). Thai Song speakers residing at two locations in Nakhon Pathom province are selected as a case study of Thai Song in the western region of Thailand. The study of phonological variation reveals that Thai Song has progressively shifted to Thai in the speech of middle and young generations. The study of lexical replacement shows that young generation speakers use fewer Thai Song words than the older generations.Australian National University16 pages"Copyright vested in the author; released under Creative Commons Attribution Licence" - at head of journal articlelanguage contacthistorical phonologylanguage shiftThai SongThai Song DamTai DamLao SongThe language shift in progress of Thai Song2013-02