There is much debate in the linguistic literature about what mechanisms are responsible for accessing, implementing, and restricting grammatical competition. Building on this line of research, this article explores competition between plural and singular marking in Western Armenian, a language where grammatical competition results in a restricted interpretation of singular nouns. Of interest to competition theories in general, this restriction only occurs in certain grammatical environments: namely, definite NPs. As argued here, an adequate treatment of these facts requires comparing utterances in terms of their syntactic complexity (as Katzir (2007) proposes).