This study investigated native Spanish speakers' acquisition of Subject-Verb Inversion (where a verbal element precedes the subject in sentences like 'What did John buy?') in L2 English. Although Subject-Verb Inversion looks superficially identical in English and Spanish single clause wh-questions, recent theoretical (Goodall 2004; Barbosa 2001; etc.) and experimental (Goodall 2011) work has argued for an underlyingly distinct syntax in the two languages. Thus, this study examines whether native Spanish speakers proficient in English represent English Subject-Verb Inversion through transfer of the underlying Spanish syntax or via a fully native-like representation. This study introduced a new tool into second language research, namely syntactic satiation, the phenomenon where repeated exposure to an ungrammatical structure makes the structure sound more acceptable (Snyder 2001; Braze 2002; Goodall 2011). In this acceptability-rating study, participants' performance averaged across the entire experiment showed no differences between native and L2 English speakers, which seemed to signal fully native-like acquisition of English Subject-Verb Inversion by native Spanish speakers. However, evidence from satiation measures showed Spanish speakers' ratings for ungrammatical English interrogatives became more lenient with increased exposure, in striking contrast to native English speakers, whose ratings stayed consistently low. This contrast suggested that even proficient L2 speakers were not representing English Subject-Verb Inversion in a fully native-like manner, and were instead transferring the structure of Spanish Subject-Verb Inversion into English.