Verb Ventures: Comparative Study on Implicit and Explicit Grammar Interventions for Multilingual Learners

Spanish-English-speaking multilinguals (MLs) with developmental language disorders (DLD) have greater difficulty with verb morphology compared to their typically developing peers. Similar patterns of errors are observed in both monolinguals and MLs with DLD. However, there are more studies that have explored the effectiveness of grammar interventions targeting verb morphology for monolinguals compared to MLs. Moreover, there are even fewer studies that compare the effectiveness of implicit and explicit approaches used in grammar intervention. Therefore, in this study with Spanish-English MLs with and without DLD in grades 3 to 5, we evaluated, using an adapted alternating treatment single-case design, the (1) effectiveness of implicit versus explicit approaches to grammar intervention that targeted the inflectional past tense –ed and third person singular –s and (2) efficiency of the implicit and explicit approaches for acquiring these grammatical morphemes. Five of the 8 participants showed stronger outcomes with explicit instruction, demonstrated by greater level changes, more rapid response to treatment, and consistent progress toward mastery, with mean accuracy approximately 5% higher than during implicit instruction. In contrast, several participants benefited more from implicit instruction, possibly due to reduced cognitive load and the influence of morphological frequency. Clinically, these results highlight the importance of tailoring intervention approaches, as responsiveness may vary depending on learners’ processing capacity and the linguistic characteristics of the target forms.