UC Santa Barbara

Recent psycholinguistic research has demonstrated that our knowledge of words includes fine-grained information about the syntactic contexts in which they are likely to participate. In these studies, the syntactic distribution of a word is defined as a probability distribution of its occurrences in various dependency roles. For example, nouns may be more or less likely to serve as the subject of a verb or as the head of an adjective modifier. In contrast to the constraint-based representations of mainstream generative theories, these syntactic distributions are gradient and probabilistic, situating words within a rich, multidimensional syntactic space.At the same time, a growing body of research has identified patterns of systematicity within and among features of the lexicon that reflect cognitive and communicative pressures on learning, memory, production, and perception. For example, the same patterns of clustering and association that are observed for lexical features are also known in the psycholinguistic literature to facilitate aspects of language acquisition and use, yet these tendencies are held in check by pressures toward distinctiveness that are crucial for perception in particular. Using corpus data from forty-eight languages, this dissertation represents the first investigation into how syntactic distributional information is patterned in the lexicon. First, I ask how syntactic representations cluster within the multidimensional syntactic space. I find that the more frequent words have denser orthographic, semantic, and—crucially—syntactic neighborhoods. At least in phonology, having many near neighbors is known to facilitate learning, memory, and production. By analogy, it seems as though the most frequent words are also the most syntactically optimized. Next, I ask if syntactic distributions participate in non-arbitrary relationships with other features of the lexicon, such as semantics and phonology. My analysis shows that, while the meanings of words are correlated positively with both their phonological forms and syntactic distributions, phonology and syntax do not share any significant correlation below the level of word class. This surprising result suggests new ideas for how functional pressures may be negotiated at different hierarchical levels within a particular lexical feature. Finally, I ask whether the syntactic distributions of words can shed light on the organization and function of other grammatical phenomena such as grammatical gender systems. I demonstrate that, while semantically and phonologically similar words are more likely to be grouped within genders, syntactically similar words are more likely to be distributed across genders. I interpret this result as a design feature of language, with grammatical gender serving to disambiguate syntactically similar words. Taken as a whole, the studies within this dissertation paint a novel picture of the role of syntax within the architecture of the lexicon. In some ways syntactic representations pattern similarly to semantic and phonological representations, and yet in other ways syntax seems to have a unique role relative to these other lexical features. The syntactic distributions of words reflect a kind of functional negotiation seen elsewhere in the lexicon, exhibiting both clustering and dispersion in different domains. The balance of such design features within the lexicon lend support to the idea that language structure is evolved for efficient use.