This paper investigates whether vocabulary knowledge and skills predict aspects of fluency. We measure vocabulary knowledge, fluency, and vocabulary skills (lexical retrieval and articulation speed). This unique approach indicates that vocabulary knowledge and skills relate to aspects of fluency, which we discuss in terms of language acquisition and testing implications.
The words second language speakers choose to use when speaking are important because of the impact selection has on fluency. In this regard, studies (e.g. De Jong et al., 2013; Uchihara & Saito, 2016) have shown that vocabulary knowledge is important for fluent speech. In terms of vocabulary knowledge, research (Fitzpatrick & Clenton, 2017) highlights the complexity of the construct, but no studies have concurrently investigated vocabulary knowledge alongside other important factors such as speed and automaticity of retrieval (Qian, 2002). The current paper, therefore, responds to this gap by exploring potential relationships between vocabulary knowledge, vocabulary skills, and aspects of fluency. 30 pre-intermediate, adult L1 Japanese users of (L2) English were measured using: a productive vocabulary task (Lex30; Meara & Fitzpatrick, 2000); a receptive task (X_lex; Meara & Milton, 2003); and the same fluency tasks (speaking and lexical retrieval speed) as in De Jong et al (2013). We explored the overlap between the vocabulary and fluency tasks using Dang, Coxhead, and Webb’s (2017) Academic Spoken Word List, and investigated potential relationships between vocabulary skills (e.g. retrieval speed) and aspects of fluency. Our findings show that vocabulary knowledge tasks are moderately predictive of some aspects of fluency. We report four additional tentative findings. First, aspects of lexical knowledge appear to be available to specific proficiency levels. Second, an overlap exists between the productive vocabulary used in response to the productive vocabulary task as well as the fluency tasks. Third, vocabulary knowledge task scores appear to indicate that participants do not have a sufficiently large lexical resource to be able to respond to specific speaking fluency tasks. Fourth, this study is the first of its kind to relate specific vocabulary skills to fluency at a particular proficiency. We discuss findings in terms of their implications for second language acquisition and testing.
