Abstract This paper draws on acceptability judgments and corpus data to investigate the alternation between infinitival (INF) and finite da -present complements (DPC) in Serbo-Croatian. We first provide experimental evidence that predictors suggested in the literature on the basis of limited empirical evidence do indeed shape complement choice: DPCs are more frequent with larger complements and root modality, while INFs are preferred with smaller complements and epistemic modality. Second, our corpus analysis shows that the previously reported effects of subject concreteness and animacy are better accounted for by subject theta role: DPC is favored by agentive subjects, INF by theme subjects. At the same time, however, we observe a notable mismatch between usage and acceptability: while speakers across the region rate both forms as acceptable to varying degrees, actual usage is sharply polarized, with DPCs prevalent in Serbian and nearly absent in Croatian. This pattern confirms the well-known finding that speakers’ intuitions preserve multiple grammatical options, while production data reveal how competing variants are resolved under communicative and normative pressure. But the discrepancy might also suggest that social meanings such as prestige, stigma, and identity, mediate production beyond grammar alone. We propose that INF vs. DPC constitutes a syntactic variable that carries social meaning, challenging claims in the sociolinguistic literature that syntax is socially inert, and we outline a research programme to identify and quantify such social meanings.
Kovačević et al. (Mon,) studied this question.