In the idioms, or idiomatic expressions, of a language, traits and aspects of a people's culture are mostly deposited and crystallized. These are generally images, intuitions, and brief illuminations that keep the connection between the present and the past alive, highlighting what is specific and typical of a language. Idiomatic means, in fact, typical, exclusive to that language, and idiomatic expression means an expressive form unique to a language, not always traceable in other languages. Comparing the idiomatic expressions of two languages means comparing two cultures, capturing some significant traits that resist the changing times and events, but it also means identifying, as in this comparison between the Greek and Italian worlds, analogies and harmonies, outcomes of a history that has seen the two peoples interact over the course of history, sharing each other's values and models in forms of mutual correspondence and influence.

This work collects, in alphabetical order based on guiding words and terms, some of the many idiomatic expressions that both languages are rich in. These are idioms chosen based on their frequency of use in contemporary Italian, their richness in terms of historical, cultural, and social references and allusions, and their correspondence with the reality of the Greek world.

For this reason, it aims to be a useful tool both for linguists and scholars who want to explore the Italian and Greek languages, and for students who want to improve their use of one of the two languages they are learning as a second or foreign language.