What 1sg forms tell us about Spanish theme vowels

Abstract

This article argues in favour of a view of the Spanish Theme Vowel (ThV) as the direct spell out of an identifiable syntactic head, specifically Ramchand's (2018) Event head, responsible for tagging lexical verbs with world and time parameters. I will argue that several apparent cases of verbal irregularity related to the conjugation of 1sg forms can be related to each other, and can receive a principled explanation once one adopts this view of Spanish ThVs. An approach where ThVs are post-syntactic morphemes that idiosyncratically tag the functional structure of verbs, or where they are syntactically inert morphemes, can only treat these facts as accidental and cannot provide an account of their mutual interconnection.