Global Cues to Spanish Differential Object Marking in Monolingual and Bilingual Child-Directed Speech

Spanish Differential Object Marking (DOM) is conditioned by well-known local properties of the direct object, but also by clause- and discourse-level factors. In this study, we examine whether these factors are also available as potential learning cues in child-directed speech (CDS). We analyzed longitudinal naturalistic CDS from two monolingual and three bilingual (heritage) Spanish-learning children, manually extracting transitive clauses and coding DOM presence alongside discourse specificity, verb class, coreferential pronoun (clitic doubling), relative animacy, and DO placement, plus two local cues for comparison. Regression analyses revealed that a wider range of local and global factors conditioned DOM in monolingual than in bilingual CDS. The potential informativeness of these factors as learning cues was quantified using Competition Model measures of availability, reliability, and validity. In monolingual CDS, local cues (+human, pronominal/proper name DOs) were highly reliable, and two global cues (clitic doubling and relative animacy) showed moderate reliability. Whereas discourse specificity and verb class were highly available, they were comparatively unreliable. Validity values were uniformly low; although several global cues matched or exceeded local cues in validity, this pattern largely reflected their greater availability rather than higher reliability. In bilingual CDS, reliability and validity were reduced across nearly all cues, with little differentiation among cues. These findings suggest that Spanish-learning children encounter potentially usable utterance- and discourse-level evidence for DOM in CDS, but that the robustness of this evidence is markedly weaker in bilingual input.