In this study, we examined two tasks of language proficiency: sentence repetition and verbal fluency (Armon-Lotem, Jong, & Meir, 2015). There is disagreement in the literature about what skills these tasks are measuring (Shao, Janse, Visser, & Meyer, 2014). In addition to measuring language proficiency, sentence repetition is often used as a task of verbal working memory, whereas verbal fluency is frequently used as a task of cognitive flexibility.

Participants were 8-12 year old English-Spanish bilingual children (testing is ongoing) who completed the Clinical Evaluation of Language Fundamentals test to measure expressive syntactic knowledge (Formulated Sentences), sentence repetition (Recalling Sentences), and verbal fluency (Word Association; Semel, Wiig, & Secord, 2010); Expressive One Word Picture Vocabulary Test-4 (Martin & Brownell, 2011), and a simple working memory span task.

The results of the model selection analysis indicate that syntactic ability explains the most variance in sentence repetition. The Formulated Sentences subtest (β=.58,p<.05) explained 44.4% of the variance in Recalling Sentences (R2=.44,F(1,8)=6.38,p<.05). No other covariates were found to be significant predictors.

Although sentence repetition has been presumed to measure both language proficiency and working memory in the literature (Polisenska, Chiat, & Roy, 2014), our results show no relationship between sentence repetition and simple working memory span.

Verbal fluency, another task of language proficiency, did not correlate with sentence repetition. In addition to language proficiency, performance this task reflects cognitive flexibility (Raskin, Sliwinsky, & Borod, 1992) that we examined by analyzing the number of subgroups/clusters and the number of switches between categories or clusters.

The findings suggest that different language proficiency tasks measure distinct cognitive-linguistic abilities, therefore these tasks cannot be used interchangeably.