Source: Dissertation Abstracts International, Volume: 79-12(E), Section: A.

Advisers: Ashwini Deo; Maria Mercedes Pinango.

Recent investigations into the sources of language change have focused on identifying the systematic patterns of variation across languages and providing generalizations that may explain these changes. These systematic developmental paths in the meanings of expression may rely on cognitively relevant properties that facilitate changes in language. This dissertation aims to provide an understanding of these cognitively relevant sources of language variation and, ultimately, stable changes in language. This question is addressed by investigating the patterns of synchronic variation in Spanish copula use across four dialects. The motivation for this dissertation relies on two main observations from previous literature. The first is a synchronic observation pointing to variation in copula use across Spanish dialects. The second is a diachronic observation indicating that, over time, the domain of use of estar has been encroaching upon the domain of ser. What is the connection between synchronic variation in copula use and the observed diachronic changes?

To address this question, I first describe the distributional patterns of the Spanish copulas with a wide range of predicate types, along with prior observations suggesting variation in copular use. Then, I present the boundedness-presupposition analysis, which relies on methodological tools from model-theoretic semantics and conceptual semantics, to account for the range of uses of estar and the variability in copula use. The analysis locates the differences between the copulas in the presuppositional component of estar, which is not present in ser. The presuppositional component is experimentally tested in four dialects of Spanish (Argentinian, Iberian, Mexican and Venezuelan) using four different methodologies: 1) an acceptability-rating questionnaire, 2) a fill-in-the-blank task, 3) a self-paced reading study and 4) an EEG/ERP study. The main finding from this investigation is that copula acceptability and use can be contextually modulated. Specifically, estar sentences increase in acceptability and are less costly to process when preceded by contextual information that satisfies estar 's pressupositional component. The EEG/ERP data provide a finer-grained understanding of the interactions between the lexical meaning of estar and the contextual information as the sentence unfolds. A main conclusion from this dissertation is that the variation observed in copula use in Modern Spanish can be understood as a manifestation of the diachronic development of encroachment of estar. The variation in copula use across dialects is a reflection of the different stages of development of estar's encroachment, with certain dialects (Mexican and Venezuelan Spanish) being further ahead in the process of encroachment than others (Iberian and Argentinian Spanish.) The dissertation concludes that it is this additional information provided by estar that speakers exploit over time and that serves as a driver of encroachment of estar over time.