The role of language proficiency, cognate status and word frequency in the assessment of Spanish-English bilinguals' verbal fluency.

Purpose: Assessment tools are needed to accurately index performance in bilingual populations. This study examines the verbal fluency task to further establish the relative sensitivities of letter and category fluency in assessing bilingual language skills in Spanish-English bilinguals.

Method: English monolinguals and Spanish-English bilinguals had 1 minute to name words belonging to a category (e.g. animals) or starting with a letter (e.g. A). Number of words retrieved, proficiency, cognate and frequency effects were examined.

Result: In their dominant language (English), bilinguals and monolinguals showed similar fluency patterns, generating more words in category than letter tasks. This category advantage disappeared for bilinguals tested in their non-dominant language (Spanish). Further, bilinguals retrieved a higher percentage of cognates (e.g. lagoon-laguna) than monolinguals across tasks and languages. In particular, as proficiency increased in their non-dominant language, bilinguals were more likely to produce cognates (including cognates with lower word frequencies).

Conclusion: While bilinguals and monolinguals performed largely the same, bilinguals showed fine-grained differences from monolinguals in both their dominant and non-dominant languages. Based on these results, it is recommended that clinicians evaluate findings from bilinguals' verbal fluency tasks with attention to language proficiency, cognate words produced and relative to normative data that match their clients' language histories.