The Learner's Interlanguage as a System of Variable Rules

Reported in this paper is a longitudinal study of the acquisition and use of the English sound system by Japanese learners of English. The central point is that the learner's second-language system must be a system of variable rules if it is to account for the variability (wide assortment of pronunciations) in his production, the fluctuations between his in-class and out-of-class performance, and the regularities in his process of acquisition. The model used in this research is the variability model of sociolinguistics. Discussed here are both the theoretical and practical values of this study. First, it captures the regular patterning of diversity in the learner's speech, giving the developing theory of interlanguagel a firmer grounding. Second, the study provides insights to help the classroom teacher better understand and evaluate student performance in pronunciation.