Three theme vowels, zero conjugation classes

I challenge the conventional understanding of Romance theme vowels (TVs) as universally identifying conjugation classes, and advance a unified and classless synchronic analysis of phi-feature exponence in Fiuman, an endangered Venetian variety spoken in Rijeka/Fiume, Croatia, and its diaspora. I propose that phi-features are exponed by the same Vocabulary Items, regardless of adjacent theme vowels. Various alternations, which give rise to the illusion of conjugation classes emerge in phonology, through the interaction between TV exponents and phi-feature Vocabulary Items, some of which have underspecified phonological structures, containing floating vocalic features. This interaction is modelled in an Optimality Theory grammar sensitive to phasal spellout. The realisation of phonologically underspecified Vocabulary Items is enforced by the Faithfulness constraint *UNREALISEDMORPHEME, argued to be a more parsimonious and modular version of REALIZEMORPHEME. *UNREALISEDMORPHEME militates against complete non-realisation of Vocabulary Items inserted in the current cycle. I examine evidence for the featural Vocabulary Items proposed based on regular verbs in the domain of irregular verbs as well as nominal and adjectival inflection, demonstrating the potential for extending the analysis to these two domains.