Usage-based Phonology proposes that language users' knowledge is stored in the form of exemplars reflecting experience of language usage. Exemplars encompass all visual and auditory information perceived during a language interaction, but few studies have examined the role that visual information plays. This dissertation addresses this question…

The occurrence of the two allomorphs of the indefinite article in standard English ("a" before nouns or noun clauses beginning with consonant sounds and "an" before those beginning with vowel sounds) is a concept similar to those studied in the general concept formation paradigm. The acquisition of this grammatical concept was examined using 80…