Proficiency Effect on the Development of L2 Derivational Knowledge

The present study examines second language (L2) learners' development of English derivational morphology and its relation to L2 proficiency. There is a limited number of empirical studies on L2 derivational morphology, particularly regarding relational, syntactic, and distributional aspects of derivational knowledge. Little is known about how these sub-aspects of derivational knowledge develop over time and how each aspect correlates to L2 proficiency. Fifty-four Chinese learners of English at three proficiency levels (intermediate, upper-intermediate, and advanced) were tested on their knowledge of morphological relatedness, syntactic categories, and distributional constraints. Results showed that L2 learners demonstrated a native-like pattern of acquiring relational, syntactic, and distributional knowledge. Learners' relational knowledge tended to stabilize once they reached and went beyond upper-intermediate proficiency, while their syntactic and distributional knowledge continued to grow. However, only intermediate learners showed moderate to strong correlations between L2 proficiency and overall derivational knowledge and between L2 proficiency and subcomponents of derivational knowledge (relational and distributional knowledge). L2 proficiency had statistically significant effects on each aspect of derivational knowledge and learners tended to score higher onwell-formed than pseudo-formed derivatives. The findings provide important pedagogical implications to instruction on derivational morphology for learners at different stages of L2 learning.