Supplemental Material for: The Cross-Linguistic Lexical Task in Tunisian Arabic: Adaptation and Pilot Evidence from Monolingual Children

Introduction: The Cross-Linguistic Lexical Task (CLT) was developed to support comparable assessment of lexical abilities across languages, particularly in multilingual clinical and research contexts. This study reports the adaptation and pilot evaluation of the CLT in Tunisian Arabic, a spoken Arabic variety for which standardized lexical assessment tools for children are limited.Methods: In Study 1, the CLT was adapted following established CLT construction principles. Adult-based adaptation metrics included naming agreement, picture and cultural appropriateness, subjective age-of-acquisition (AoA) ratings, and complexity-index (CI) screening. The initial adaptation pool comprised 322 picture/word candidates, of which 299 were retained after CI screening for final item selection. In Study 2, the adapted CLT was piloted in 13 monolingual Tunisian Arabic-speaking children recruited in Tunisia.Results: Tunisian Arabic AoA estimates showed strong correlations with the mean AoA of a seven-language CLT comparison dataset (Pearson's r = .70; Spearman's ρ = .69), supporting their cross-linguistic plausibility. During the pilot administration, overall accuracy was high but varied across subtasks: noun comprehension = 96.4%, verb comprehension = 93.5%, noun production = 95.0%, and verb production = 83.9%. Verb production was the most demanding condition and demonstrated the greatest inter-individual and item-level variability.Conclusion: The findings support the feasibility and linguistic appropriateness of the Tunisian Arabic CLT and provide an important foundation for future normative data collection, reliability studies, and clinical validation in Tunisian Arabic-speaking children.