This is the companion repository for the study with the same name.
This study analyzes the use of future verb forms in Spanish generated by large language models (LLMs) in order to evaluate whether these systems reproduce a linguistic variable undergoing change: the progressive displacement of the morphological future (cantaré) by the periphrastic future (voy a cantar) in contemporary Spanish. Based on a controlled multiple-choice experiment, it examines the preference for the morphological future or the periphrastic future across different contexts (prospective and epistemic) in the output of seventeen contemporary language models. The results show a general tendency toward the morphological future, although with notable differences across models. The analysis reveals not only patterns of linguistic behavior but also biases stemming from training data and processes. This study contributes to the emerging field of linguistic evaluation of LLM in Spanish.
Publication Date: 2026-06-18