We still know surprisingly little about how grammatical structures are selected for use in sentence production. A major debate concerns whether structural selection is competitive or noncompetitive. Competitive accounts propose that alternative structures or structural components actively suppress one another's activation until one option reaches the threshold for selection, whereas noncompetitive accounts propose that grammatical structures emerge as a result of incremental processes that generate an utterance in a piece-by-piece fashion, without direct competition between syntactic components. In this dissertation, I test the hypothesis that a competitive structural selection mechanism may function in tandem with more general incremental processes. Most importantly, I manipulated the structure of prime sentences (active and passive), and also included an unrelated control prime condition (intransitive structure) in order to clearly segregate facilitatory and competitive effects. Syntactic flexibility was manipulated by constraining structural choices or leaving them open. To fully explore syntactic and lexical processes, experiments also manipulated two kinds of verbs (normal agentive verbs and theme-experiencer verbs), verb repetition, and lexical priming of sentence arguments. Dependent measures included structural choices for the unconstrained conditions and initiation latency for all conditions. Across five experiments, results did not consistently show effects of structural priming on syntactic choices for unconstrained targets, or on reaction time. Consequently, there was also no evidence of competition in terms of reversals of choice rates or slower initiation of unprimed structures. Despite this, there was some evidence of increasing passive use within experiments. Given the weak priming effects, the patterns of errors and reaction times were assessed outside of the priming manipulations. The results of these comparisons generally indicated that production was faster and less error-prone in the unconstrained conditions, consistent with a noncompetitive account, and largely replicating Ferreira (1996). The experiments also demonstrated dramatic differences of flexibility for the two different sub-types of verbs. As a whole, this dissertation provides little evidence for syntactic competition during structural selection in sentence production. However, a definitive test of competition in grammatical formulation must await a more successful manipulation of immediate structural choices. [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.]