The pronunciation and use of /s/ in the isleno dialect of Spanish, a dying language spoken in a small ethnic enclave in southeast Louisiana, is examined. Today, there are fewer than 20 fluent speakers of isleno Spanish, which has been described as a fossilized derivative of the speech of Canary Island peasants with additions from Spanish sailors. The aspiration or deletion of /s/ in various contexts is an overt linguistic indicator of isleno speech that members of the isleno social network recognize as a feature of their language. This paper demonstrates that /s/ plays a prominent role in style-shifting for all islenos; e.g., a semi-speaker deletes /s/ much more frequently in casual conversations with in-group members than in a dyadic interaction with an out-group interviewer. The frequency of /s/ deletion of the semi-speaker is much higher than that of the Spanish-English balanced bilingual, suggesting a process of speech accommodation. Additional differences between semi-speakers and fluent speakers are discussed. Contains 22 references. (LB)