Consul tertium o consul tertio? Dubbi metalinguistici, sincretismo e variazione nelle formule di iterazione delle cariche pubbliche

In a passage of his Noctes Atticae, Aulus Gellius discusses the matter of whether the adverbial form tertium or tertio should be used to refer to someone who was holding a magistracy “for the third time”. The debate is a consequence of a functional equivalence that is currently recognised by the Latin reference grammars: with the exception of iterum “for the second time”, the frequency adverbs indicating ordinal rank in a sequence are derived from the ordinal numbers, either in the accusative form (tertium, quartum, etc.) or in the ablative form (tertio, quarto, etc.). Following a sociolinguistic approach, the distribution of accusative-based and ablative-based forms is analysed in both epigraphic and literary texts. This pattern of variation is seen as part of a more general and long-term process of linguistic change, i.e. case syncretism, whose system’s internal mechanisms are discussed in the light of diachronic typology, with particular reference to their multifactorial causes.