Psychometric Properties and Diagnostic Accuracy of Spanish BESA Morphosyntax and Sentence Repetition in Mexican Children

Introduction: Accurate identification of developmental language disorder (DLD) requires assessment measures validated for their intended populations. This study examined the psychometric properties and diagnostic accuracy of preliminary Spanish grammatical measures from the Bilingual English–Spanish Assessment (BESA) in monolingual Mexican children. Method: Participants included 395 monolingual Spanish-speaking children aged 3;0–5;5 years (295 typically developing, 100 with DLD). Twenty-two grammatical cloze items and 53 sentence repetition targets were examined using regression, classical item analyses, item response theory, receiver operating characteristic analyses, and repeated cross-validation.Results: Children with DLD performed significantly below typically developing children on both tasks, while scores increased with age. Clitic pronouns and subjunctive constructions demonstrated strong item-level discrimination, and two-parameter item response models fit better than one-parameter models. The 21-item Morphosyntax score yielded an area under the curve of .872, compared with .847 for the 29-target Sentence Repetition score. Combining both tasks yielded .885, although the improvement in discrimination was not statistically significant. Discussion: Findings provide promising evidence of the diagnostic utility of preliminary BESA Spanish grammatical measures in monolingual Mexican children and highlight the importance of item-level evaluation and population-specific validity evidence. Further research is needed to evaluate the complete published assessment, establish clinical cutoffs, and compare item performance across monolingual and bilingual populations.