Document Type


Date of Degree

Summer 2009

Degree Name

PhD (Doctor of Philosophy)

Degree In


First Advisor

Roumyana Slabakova

First Committee Member

William D Davies

Second Committee Member

Elena Gavruseva

Third Committee Member

Paula M Kempchinsky

Fourth Committee Member

Jason Rothman


The primary objective of this dissertation is to expand the testing ground of the Interface Hypothesis (Sorace, 2006), which states that interface properties involving the syntax and other cognitive domains (such as discourse) may trigger residual optionality effects at the end-state. The target of investigation were Bulgarian object clitics whose syntactic and discursive properties provide a good testing ground for theoretical approaches to second language acquisition. Ten advanced and 14 intermediate L2 speakers of Bulgarian, as well as a control group of Bulgarian native speakers, participated in the study. The test materials included a proficiency test, a grammaticality judgment task to check syntactic knowledge of clitics, and a pragmatic felicity task. The latter was aimed at investigating the degree to which L2 learners of Bulgarian, with English as their L1, had acquired a syntax-discourse interface property of Bulgarian, namely the pragmatic function of clitic doubling. In Bulgarian, clitic doubling serves as an overt marker of topicality and `undoubled' object topics are deemed infelicitous.

The results of the experiments in this dissertation present a challenge to some theoretical approaches to second language acquisition, namely the Interpretability Hypothesis (Tsimlpi and Dimitrakopoulou, 2007) and the Interface Hypothesis (Sorace, 2006). The results showed that the intermediate participants did not differentiate between the felicitous and the infelicitous options in the pragmatic felicity task in a target-like manner as their responses either did not exhibit statistically significant difference or favored the response closest to the L1. However, the advanced L2 learners of Bulgarian had successfully acquired the syntax of clitics as well as the pragmatic meaning of clitic doubling in Bulgarian. They displayed target-like convergence with respect to the syntactic properties of Bulgarian object clitics and distinguished between the felicitous and the infelicitous options in the pragmatic task in a native-like manner.

The study highlights the fact that successful learning at the syntax-discourse interface cannot be excluded and a lot more research, exploring as many interface conditions as possible, needs to be done in order to validate the Interface Hypothesis as a legitimate constraint which permanently hinders native-like performance.


acquisition, Bulgarian, clitics, interfaces


xvi, 195 pages


Includes bibliographical references (pages 185-195).


Copyright 2009 Ivan Prodanov Ivanov

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