In this dissertation I deal with modal expressions and their contribution to discourse. In particular I deal with presuppositional clitics and modal adverbs. I argue that presuppositional clitics make presuppositions persist in all kinds of modal contexts. Modal adverbs such as obviously really certainly trigger conversational implicatures in discourse.
Two books have been based on this dissertation:
Dilemmas and excogitations: an essay on modality clitics and discourse, Messina, Armando Siciliano
Modal adverbs and discourse, Pisa, edizioni Tecnico Scientifiche.