The Syntax-semantics interface in L2 acquisition: genericity and inflected infinitive complements in non-native Portuguese

Contemporary acquisition theorizing and studies have argued and empirically supported the claim that interfaces of syntax and other linguistic modules are particularly vulnerable in L1, bilingual and especially L2 acquisition (Platzack, 2001, Montrul, 2004, Muller and Hulk, 2001, Sorace, 2000, 2003, 2004, 2005, Serratrice et al., 2004, Paradis and Navarro, 2003, Valenzuela, 2006 Zapata, Sanchez and Toribio, 2005). Stemming from seminal work by Sorace (2000, 2003, 2005), much contemporary research in generative SLA has focused on the acquisition of interface properties under the assumption that while the acquisition of the narrow syntax is straightforward for adults, postcritical period acquisition of interpretation and discourse usage seems to lag behind, often dramatically. For some researchers, interfaces are unavoidably a locus for non-convergence (e.g. Valenzuela, 2006), which is to say, there is a debate as to whether or not L2 learners can actually acquire interface-conditioned properties at all. Sorace and colleagues contend that interfaces (e.g. the syntax-semantics, syntax-pragmatics and the syntax lexical-semantics interfaces) are especially vulnerable for adults and therefore subject to greater difficulty, delays, and result in so-called residual optionality (e.g. Belletti and Leoni, 2004, Fruit, 2006, Papp, 2000, Sorace, 2004, Sorace and Filiaci, 2006, Tsimpli and Sorace, 2006, Unsworth, 2004, Valenzuela, 2006). Recently, it has been argued that not all interfaces pose the same level of complexity/difficulty in adult acquisition, which is to say the syntax-pragmatics interface seems to be a source of greater L2 non-convergence as compared to the syntax-semantics interface (Tsimpli and Sorace, 2006, Valenzuela 2006). This is not necessarily unpredicted in light of observations from L1 and bilingual acquisition and the very nature of this particular interface, where syntax and discourse structure meet. Research has shown L1 developmental delays and adult variability for properties at the C-domain for monolinguals and demonstrates greater incidences of cross-linguistic interference, attrition (i.e., the erosion of pragmatic features) and variability at this interface for bilingual acquisition (Fruit 2006, Montrul, 2004, Muller and Hulk, 2001, Paradis and Navarro, 2003, Platzack, 2001, Serratrice at al., 2004, Tsimpli et al., 2004, Zapata et al., 2005). Since semantic knowledge is mediated by the syntax, it is intuitive to predict that properties at the syntax-semantics interfaced would be easier to acquire than those at the syntax-pragmatics interface, but still harder that properties within the narrow syntax in light of an added layer of