The study abroad (SA) experience is often viewed as an opportunity to gain proficiency in a foreign language due to immersion in the target language and culture. Nevertheless, the increased amount of research conducted on SA over the last two decades indicates that it does not necessarily lead to gains in all areas (Collentine & Freed, 2004; Lafford & Uscinski, 2014; Segalowitz, Freed, Collentine, Lafford, Lazar, & Diaz-Campos, 2004). Recent research has suggested that one area in which gains are often made during SA is in the acquisition of dialectal features. However, the growing amount of research that has been conducted on this topic in Spanish-speaking contexts has focused primarily on second language (L2) learner development of features specific to North-Central Spain and has not been able to fully explain the individual variation in production of such features (see Geeslin & Gudmestad, 2008; George, 2013, 2014; Knouse, 2013; Reynolds-Case, 2013; Ringer-Hilfiger, 2012, 2013). Since Argentina is one of the top Spanish-speaking SA destinations (Institute of International Education, 2016), learner production of features characteristic of Argentine Spanish should also be investigated. This study quantitatively examines learner production of phonological and morphosyntactic features characteristic of Buenos Aires Spanish, sheismo/zheismo and voseo. Participants were 23 L2 learners of Spanish studying abroad for a semester in Buenos Aires, Argentina. Speech data--which included over 5,000 phonological tokens and over 1,200 morphosyntactic tokens--were gathered prior to, at the mid-point, and at the end of the semester by means of sociolinguistic interviews and a series of elicitation tasks. These data were analyzed for the influence of linguistic and social factors by means of quantitative sociolinguistic analysis using a mixed-effects model (Rbrul; Johnson, 2009). Specifically, these data were correlated with social networks using the results of a social network strength scale (SNSS; Kennedy, 2012; Milroy, 1980) adapted for the SA context. Results indicate that learners moved towards target-like norms of use of these features, significantly increasing production of vos and sheismo/zheismo during the semester abroad. Additionally, social networks with native speakers in the host community were statistically significant predictors of increased use of vos but not that of sheismo/zheismo. These findings contribute to the understanding of the role of SA in language learning by demonstrating the importance of social networks with native speakers of the target dialect in the acquisition of region-specific features in the SA context. Furthermore, this study provides one of the first accounts of the acquisition of features characteristic of a dialect of Spanish spoken in Argentina. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]