Purpose: This study examined the latent dimensionality of Spanish in young Spanish-English dual-language learners (DLLs). Method: Two hundred eighty-six children participated. In their prekindergarten year, children completed norm-referenced and experimental language measures in Spanish requiring different levels of cognitive processing in both receptive and expressive language modalities. Results: The best-fitting model suggested a bifactor solution with a single general language factor "L" plus two additional factors "word knowledge" and "integrative language knowledge." The general trait "L" reflects the proportion of common item variance for all of the items, and the group traits of word knowledge and integrative language knowledge explain additional domain-specific variance for those item subsets. Conclusion: Results suggest that the Spanish language in preschool-age Spanish-English DLLs is not separable into content, form, and use, nor is it separable by higher- and lower-level language domains or processing demands. Instead it appears that a general language factor underlies oral language in Spanish in DLL preschoolers and that other factors account for additional variance over and above "L." Findings are discussed in relation to a companion study of monolingual English-speaking prekindergarteners. [This article was prepared by a Task Force of the Language and Reading Research Consortium (LARRC).]