Examining the Effect of Word-Formation Instruction on Moroccan EFL Learners’ Vocabulary Development

Abstract

This study examines the impact of word parts instruction (WPS) on vocabulary development among Moroccan EFL university students at Mohammed V University in Rabat. Specifically, this study aims to (i) measure the students' vocabulary breadth, (ii) to investigate the effect of Word Parts Strategy instruction on L2 vocabulary development. Data were collected pre- and post-treatment using the Vocabulary Size Test (VST) and Word Parts Strategy Tests A and B. The pre-tests assessed participants’ pre-existing vocabulary knowledge. The posttests were administered to identify the effect of word parts instruction on the students’ vocabulary knowledge. The quantitative and qualitative data were statistically analyzed via the Statistical Package for Social Sciences (SPSS. The study found significant differences between the experimental and the control groups’ vocabulary learning after the treatment, and the differences were positive in favor of the experimental group. The experimental group demonstrated a statistically significant gain in total vocabulary size following WPS instruction, suggesting that the strategy positively impacted vocabulary learning. The findings reveal that the experimental group not only outperformed the control group but also demonstrated substantial gains in both vocabulary breadth and depth, confirming the pedagogical efficacy of the Word Parts Strategy instruction in university EFL settings.