Input factors in child ESL acquisition of the past tense

Various dual- and single-route models have been proposed to account for the storage and processing of morphologically complex forms. This thesis evaluates the predictions of Bybee's single-route, Usage-based model (1995, 2001) with respect to the role of type and token frequency in the input and the acquisition of the English past tense. Data for this study were collected from a larger longitudinal study of 17 ESL children. At each of three testing rounds, a spontaneous language sample was recorded and a standardized elicitation task and receptive vocabulary size measure were administered. The frequencies of regular, irregular, and regular allomorph past tense forms in the input and the children's accuracy in the production of these forms were examined at each testing Round. The implications of these results for predictions of the Usage-based model as well as for the dual- vs. single-route processing debate are discussed.