Si eso: la emergencia de una «partícula modal» en el español del siglo XXI

The present article tackles the study of the new conditional expression si eso in 21st century Spanish. Based on the analysis of a representative corpus of colloquial written Spanish, over a hundred instances of this emerging particle are examined. As the main hypothesis, this expression is described as a modal particle and its functions are looked for within the components of illocutionary act, particularly as a mitigation device for weakening the speaker's commitment to the truth of propositional content, as well as to the obligations assigned to the hearer. Three primary values are proposed for this particle (eventuality, necessity, and scalarity), along with some formal indicators that materialize these semantic distinctions. The development of this particle represents a challenge for historical linguistics and semantic-pragmatic studies, as its polysemy and polyfunctionality is deploying in real-time.