The role of discourse context and verb class in native and nonnative Spanish postverbal subject

Recent research on the second language (L2) acquisition of postverbal subjects in Spanish has focused on the important role of discourse context in licensing postverbal subjects with unaccusative and unergative verbs (Hertel, 2003; Lozano, 2006; Dominguez & Arche, 2008; Dominguez, 2013). While these studies have made important advances in early L2 research within the generative framework, in which the structure was studied as a part of the pro-drop parameter (White, 1985; 1986, Liceras, 1988; 1989), they only examine intransitive verbs, do not consider the role of nuclear stress, and do not compare postverbal subject use across discourse contexts nor include contrastive focus as a discourse context. These shortcomings have led to variable performance by the native speaker controls, which make any claims of native or non-native like performance on the part of L2 learners questionable. This dissertation uses empirical data to incorporate discourse context, verb type, and nuclear stress into one experiment examining postverbal subjects in Spanish by native speakers and English-speaking L2 learners. A multi-componential experiment was conducted, consisting of two oral assessment tasks, in order to gauge native speakers' and L2 learners' ability to produce and rate sentences with postverbal subjects compared to those with preverbal subjects. It considers three discourse contexts: wide, narrow, and contrastive focus, four verb types: unaccusative, unergative, transitive, and ditransitive verbs, and transitive verbs with topicalized objects. Ninety-five L2 learners from four proficiency levels and thirty-seven native speaker controls completed the study. Results show that for the contexts in which native speakers most frequently use postverbal subjects, namely with topicalized objects and in contrastive focus, L2 learners from low through advanced proficiency can also use postverbal subjects, and knowledge of postverbal subjects increases significantly with proficiency. The optionality of pre- and postverbal subjects in narrow and contrastive focus is explained syntactically by positing a null pro[FOC] that can optionally be used in the numeration along with the lexical subject when it bears matching agreement and focus features. The Feature Reassembly Hypothesis (Lardiere, 2008; 2009) can explain L2 behavior by positing difficulty in reassembling the features from one lexical item in English, the lexical subject, to two lexical items in Spanish, the lexical subject and pro[FOC].