This dissertation reports the results of an ethnographically informed, variationist sociophonetic account of the acquisition of vernacular English dialect features by adolescent Roma migrants attending a Manchester high school. As one of the first studies of Romanian Roma acquisition of English, this work speaks to ongoing discussions about migration, integration, and social factors impacting upon language acquisition. I also address discussions concerning methodological approaches to and the importance of the study of the acquisition of sociolinguistic competence in a new language. Recently, Manchester has seen an influx of Roma migrants. Previous research suggests that migrants can acquire local patterns of variation in a new language and that social networks may impact upon this acquisition. What remains unclear is why certain speakers acquire more local features than others. The findings of this study contribute to knowledge through the use of a mixed methods approach combining quantitative analysis of speech data with ethnographic observations to provide a fine-grained, methodologically robust analysis of linguistic variation. I report analyses of three vocalic variables. Results indicate that speaker’s friendship networks have a statistically significant effect on linguistic production. The more open speakers’ friendship networks are, the more likely they are to reproduce local patterns of variation. Ethnography exposes the unreliability of participants’ self-report data on friendships and give context to the quantitative results, indicating complex interactions between speakers’ Roma and local identities. These findings give weight to the argument that more mixed methods variationist SLA research is needed. Increasing superdiversity in urban centres make this an important area of research both for the experience of migrants and those who live in the countries they move to. Where there is evidence of dialect acquisition, this can be seen as an indicator of the way in which an individual is positioning himself or herself within the local culture.