It is generally believed that study abroad (SA) is the most efficient and successful way to acquire proficiency in a second language (L2). SA is a crucial component of students' second language acquisition (SLA) process, for it puts them in situations in which they can use the language on a daily basis and interact with native speakers. More than two decades of research focused on the second language outcomes of Spanish immersion programs has produced a wealth of studies documenting the weaknesses and strengths of Spanish immersion students' communicative proficiency. For the most part, these studies have concentrated on L2 learners' acquisition of features of the target language, typically measured by categorical, as opposed to variable, standards. Consequently, many questions pertaining to the acquisition of patterns of language variation common to a particular community in a SA context remain unanswered. This dissertation explores the extent to which L2 learners of Spanish acquire variable structures of language--specifically, the "leismo" phenomenon, i.e., the use of the dative pronoun "le(s)" instead of the accusative pronouns "lo(s)" and "la(s)" as direct objects--while participating in a five-month study abroad immersion program. The research is comprised of two groups (N = 40; n = 20 per group) of L2 learners of Spanish studying in two different regions of Spain where "septentrional" (Valladolid, Castilla-Leon) and "meridional" (Sevilla, Andalucia) dialects make this linguistic variation salient. In addition, baseline data from native speakers of both regions (N = 36; n = 18 per group) is compared to that of the L2 learners of Spanish. The present study is a quantitative and qualitative longitudinal investigation of oral and written data, which were elicited respectively through sociolinguistic interviews and written tasks with participants. The results suggest that SA learners do in fact develop an awareness of non-standard forms of the target language, which are, to a certain degree, incorporated into their sociolinguistic competence. In sum, this project contributes to an extensive body of research on the SLA of object pronouns by adding qualitative and quantitative longitudinal data, and helps to add further knowledge about the development of L2 linguistic competence during a sojourn abroad, and to fill a gap in the new strand of studies on the acquisition of sociolinguistic variation due to L2 learners' exposure to the target speech community. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html) [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]