This paper focuses on sociolinguistic variation in the Arabic spoken in northern Oman, referring to the notions of saliency and prestige, along with the role of indexicality, geographical mobility and identity affiliation, to explain why some local variants persist while others are being leveled out. Data is based on interviews with two groups; the first has thirty-eight speakers of a sedentary dialect who migrated from the hinterland city of Nizwa to the capital Muscat and the second includes forty members from a settled community in Suwaiq, a town with a mixed Bedouins population. The study examines the sedentary group’s use of the second-person feminine singular suffix and their use of the traditional interrogative clitic, which is suffixed in yes/no questions. In the Bedouin group, the phonological variation in the use of the voiced affricate is investigated along with the use of the definite article, which is sometime deleted in the vernacular. Analyses reveal that the local forms for the feminine suffix and the traditional variant of the affricate prevail among speakers of the respective dialects. The survival of these local forms can be attributed to their saliency, their high presence in other varieties and prestige. Conversely, the local forms for syntactic variables from both dialects are shown to be generally disfavored. We argue that the shift from these vernacular forms is triggered by speakers’ contact stimulated by social and geographical mobility and their role in indexing speakers’ identity affiliation.