Loss of unreleased final stops among Mandarin-Min bilinguals: Structural convergence of languages in contact

The two languages of a bilingual speaker are interconnected and mutually influence linguistic forms and structures. This study presents a case in which two languages in contact exhibit phonotactic asymmetries but converge on abstract phonological units by bilingual speakers. The specific case examined here concerns the change-in-progress of unreleased final stops among young Mandarin-Min bilingual speakers in Taiwan. Phonotactically, obstruent finals are illegal in Taiwan Mandarin, whereas Taiwanese Southern Min (TSM), a local substratum language, allows obligatorily unreleased final stops. In the discrimination of stimuli modeled after TSM, bilingual listeners were consistently outperformed by Korean listeners, a non-native reference group without restrictions against obstruent finals. A follow-up production study revealed that final stops produced by the bilingual speakers were prone to deletion accompanied by vowel lengthening, similar to a long vowel in an open syllable, as well as frequent substitution. Furthermore, strong correlations were found between bilingual speakers’ perception and production accuracy, indicating a bidirectional co-evolution between perception and production during language development. Taken together, the results suggest that a loss of unreleased final stops is underway in TSM through the structural convergence of two interacting phonological systems within bilingual individuals.