This thesis investigates the microsyntax of articles and personal pronouns in the medieval varieties of Lombardy and Veneto (13^th–15^th century). The study combines functionalism and grammaticalization theories with the principles of pragmatics and textual linguistics. The investigation draws upon a corpus of 47 texts selected to ensure representativeness across various diaphasic and diastratic varieties.

The emergence of the article was analyzed based on syntactic, pragmatic, and semantic constraints. The analysis shows that syntactic instances exhibiting stronger diachronic resistance to the grammaticalization of the article are prepositional phrases, enumerations, and vocative phrases. Concerning pragmatic constraints, the definite article is generally required in the presence of universally known and unique referents as well as with inalienable possession. With respect to semantic constraints, there is greater fluctuation in the alternation between zero article and the definite article. The semantics of special noun classes (namely proper names, kinship terms, and abstract nouns) exerts greater resistance to the grammaticalization of the determiner. Overall, by the 14^th century  in both Lombard and Venetan varieties, the definite article exhibits an advanced functional stage along the cline of grammaticalization. With respect to the indefinite article, uno is fully grammaticalized as a marker of specific indefiniteness while still competing with other constructions for marking non-specific indefinite referents. Moreover, the analysis attests to the early instances of partitive nominal constructions and partitive articles.

Regarding the personal subject pronouns, their microsyntax was analyzed with respect to three interdependent phenomena characterized by complex processes of polymorphism, polyfunctionality, and reorganization of syntactic systems. On the expression of pronominal subjects (PS), the quantitative analysis highlights that the rate of PS expression is strongly dependent on the type of proposition, namely main, coordinate, and subordinate. Notably, the PS is generally expressed in main clauses and subordinate clauses, notwithstanding the presence of functional restrictions. This indicates a system where the expression of PS is typically obligatory in both clauses, conflicting with the so-called “asymmetric pro-drop” hypothesis. The analysis shows that the emergence of a new tonic paradigm of PS, developed from the oblique pronouns, is associated with special syntactic and pragmatic conditions. However, from the mid-14^th century onward, the new tonic forms appear more frequently in the canonical subject position, signaling the rise of a new paradigm. This phenomenon coincides with the parallel emergence of subject clitics. Based on four syntactic criteria, the evidence hints at the development of a clitic subject paradigm exhibiting characteristics of a classic grammaticalization process such as weakening and cliticization.

All in all, this thesis underscores the complex linguistic landscape of medieval Italy, and argues that the evolution of articles and personal pronouns in these substandard varieties aligns with the predictions from grammaticalization theories, providing insights into the dynamics of linguistic change.