This dissertation examines the syntactic positions of nominal arguments in Turkish, looking at Turkish clausal structure based on Aktionsart (aspectual) properties (e.g. Vendler 1967) of (dynamic) predicates from the perspective of Antisymmetry (Kayne 1994). It has been argued that indefinite/non-specific arguments appear syntactically in lower positions than definite/specific arguments in some languages. While definite/specific arguments can be scrambled away from their base positions, indefinite/non-specific ones stay in situ (e.g. de Hoop 1992; Diesing 1992; Kornfilt 1984). Even though previous studies have shown that in Turkish specific arguments appear syntactically higher than non-specific arguments (e.g. Kennelly 1994; Zidani-Erothlu 1997; Kelepir 2001), the question of where exactly they appear within a particular syntactic domain has not been clearly addressed. Based on the syntactic position and the behavior of Turkish nominals and (low) adverbs, I argue that a bare internal argument does not occur in the complement position of a verb; rather, it occurs in the specifier position of VP (cf. Larson 1988). The current proposal has important implications for Turkish clausal architecture: (i) Aktionsart (aspectual) properties of predicates play a crucial role in determining their syntactic structures, (ii) there is an aspectual projection (AspP) in accomplishments/activities, but not in achievements; this study thus provides evidence that the Vendlerian/Dowtian distinction between accomplishments and achievements is syntactically real, and (iii) clause structure obeys (a weak version of) Antisymmetry. This study also provides implications for the relation between syntax and information structure. I show that the syntax-prosody boundary is associated with the semantic boundary between the presuppositional and the non-presuppositional interpretations, which is (at) the edge of vP. Crucially, the edge of vP serves as the boundary for both prosody and presuppositionality (at least in Turkish). This syntactic boundary/domain interacts with the information structure where topic/focus elements in discourse contexts are placed in particular syntactic position/domains. Languages use different linguistic cues/strategies in the realization of topic/focus. Such linguistic signals are typically the same as the signals for marking grammatical functions (e.g. case morphology, agreement, word order, and so on). In the case of Turkish, definite/specific DPs (and topics) occur above TP (SpecTP/SpecTopP) and indefinite/non-specifics (foci) occur within vP (SpecvP and SpecVP) (or a immediately pre-verbal position). Those particular syntactic specifier positions are clearly associated with the role of topic-comment/information structure, not just grammatical functions. It has been shown from Turkish data that syntactic positions of nominals (scrambling/word order) and prosodic prominence interplay in order to signal and maintain the topic-comment/information structure, which can also be observed across languages (such as German and Russian). Both word order and prosody are necessary to realize the information structure in Turkish; thus, neither syntax nor prosody should be reduced. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]