Re-examining the relationship between productive vocabulary and second language oral ability

Abstract

Vocabulary knowledge is considered to be an essential component of L2 proficiency. To test this assumption, a great number of studies have thus far explored the relationship between vocabulary and language skills (e.g., reading). The current chapter follows this line of research but focuses on the understudied relationship between vocabulary and speaking. This study investigates the relationship by examining the extent to which L2 productive vocabulary knowledge can predict global, temporal, and lexical dimensions of speech production. Forty participants (L1 Japanese), with varying degrees of L2 English proficiency, completed a productive vocabulary task (Lex30; Meara & Fitzpatrick, 2000) and a spontaneous speaking task (i.e., oral narrative). Our data indicate that productive vocabulary knowledge is associated with oral fluency (articulation rate and silent pause ratio), which might to some degree indirectly contribute to native listeners’ global judgements of comprehensibility (ease of understanding). Our data also highlight an important relationship between productive vocabulary knowledge and lexical richness (sophistication and diversity). Different scoring systems of the vocabulary task performance reveal varying degrees of relationship between productive vocabulary and oral ability. Based on these findings, we discuss implications for assessing vocabulary, and highlight several potential avenues for further research in this area.