This inquiry focuses in the description and analysis of diglossia and bilingualism as linguistic phenomena highlighting cultural alternation or alternative approaches within the Muslim community settled in San Andres Island, in the Colombian insular Caribbean. An ethnographic method for speech and sociolinguistics was followed, which led us to find that Arabic language, in their classical and dialectal variances, has everyday usage in the island. Also, we could observe a language contact situation between Arabic and Spanish languages, which allow us define the island as a contact zone. We can conclude that diglossia and bilingualism are proofs of cultural alternation in everyday life, that is, a displacement occurs between cultural signification spheres, implying changes and variations in the processes of identity-construction among this speech community members.