Meaning through Time: A Diachronic and Semantic Study of Italian Free Choice Marco Degano Abstract: Formal semantics and historical linguistics have been often considered two distinct and unrelated disciplines, studied by different people with different methodologies and different concerns. The aim of this thesis is to bring them together. Our case study is the Italian indefinite determiner qualsiasi, which exhibits Free Choice functions. We adopt an implementation in Hamblin semantics for the analysis of Free Choice, where qualsiasi is associated with a default [∀] operator. We employ corpus-based tools to build a database of our item from its origin to its current usage with more than 500 examples. We show how the diachronic studies motivate the presence of the [∀] operator in our formal treatment of Free Choice. We use our database, together with information obtained from historical dictionaries, to reconstruct the grammaticalization phases of the indefinite determiner qualsiasi. We show how a semantic compositional treatment of qualsiasi can be integrated in our diachronic investigation, explaining how the mode of composition changes in each phase. In the second part of the thesis, we extend our semantic framework to account for the contribution of un qualsiasi (the combination of qualsiasi with the indefinite article un), which exhibits other readings beyond Free Choice. We motivate its existential quantificational force by working at the syntax-semantics interface. We analyze some of the readings associated with un qualsiasi by means of a conventional implicature or by the loss of the indefinite status of qualsiasi in favour of an adjective-like treatment. Overall, the thesis contains a few comparisons with previous accounts of Free Choice, some methodological reflections regarding the integration of formal semantics with historical linguistics and several directions of future research.