Accounts of second language (L2) acquisition that recognize a social dimension of language use have long been in existence and have received additional attention since the publication of the seminal work by Canale and Swain (1980), who argued that communicative competence in a L2 entails not only knowledge of the grammar of a language but also of how to organize discourse, make requests for clarification and use language appropriately in a given context (eg, Li 2010; Mougeon, Nadasdi & Rehner 2010). In other words, it is agreed that a competent language user interprets language according to context and varies his or her own production based on features of the discourse setting (albeit subconsciously). Moreover, it is generally recognized that social contexts may affect the provision of input and/or feedback, language processing and sequences of development and it has been argued that cognitive models of development simply cannot ignore these facts (Firth & Wagner 1997, Tarone 2007). One approach to identifying and understanding the role of social factors in L2 learning and use comes from variationist linguistics. The potential contributions of this field include the ability to study cross-linguistic influence, provide a realistic view of the target, examine restructuring in L2 grammars, and explore the process of moving beyond the classroom variety (Bayley & Preston 2008). The purpose of the current paper is to highlight some of the recent advances in variationist research on L2 Spanish and to provide a more detailed look at one particular case of such developments: the examination of the role that individual lexical items play in the use of variable structures, such as the copula contrast, by L2 speakers of Spanish.

Research conducted within the variationist framework has examined a wide range of grammatical structures in L2 Spanish, including the copula contrast, mood contrast, forms of subject expression, object pronouns, the present progressive, the present perfect, forms of future time reference, intonation, the interdental fricative and/s/-weakening (see Geeslin 2011 for a detailed review). Clearly, one of the greatest developments in variationist research on L2 Spanish has been the rapid growth in this field of inquiry, which until recently was more limited to work on L2 French and English (see Geeslin & Gudmestad 2010 for a review). In addition, however, there are several substantial findings and methodological advances that merit attention. For example, research on L2 acquisition of variable structures such as the copula contrast (Geeslin 2000, 2003), the mood contrast (Gudmestad 2012b), object pronouns (Geeslin, García-Amaya, Hasler Barker, Henriksen & Killam 2010), differential object marking (Killam 2011) and the perception of aspiration (Schmidt 2011) has connected variationist research to mainstream research on the stages of L2 acquisition, demonstrating that variable structures are indeed acquired in a similar manner to those that are not variable. Additionally, this field has been bolstered by the inclusion of native speaker baselines which provide a more accurate view of the target toward which L2 learners are moving (eg, Geeslin, García-Amaya, Hasler Barker, Henriksen & Killam 2010). Variationist studies have also served to move the field forward in the definition and operationalization of existing linguistic factors that serve to describe the use of variable structures. For example, Woolsey (2008) developed a methodology through which the effects of contexts of comparison on the copula contrast could be examined, Gudmestad and Geeslin (2010) explore competing definitions of the term ambiguity and show how these …