The “Purple Book” (English Grammar for Students of Italian) makes a good introduction to this concept and presents the informal subject pronouns “tu” and “voi” and the formal subject pronouns “Lei” and the less commonly used “Loro”. See pages 31-34 in the printed version of the purple textbook or view pages 76-82 in the digital version online.

The formal you is expressed as Lei. The informal is expressed as tu or voi and is used with family members and close friends; people you would address by their first name. In the formal dialogues you have listened to, you heard some of these words as well as the greeting “buon giorno”. We will continue to hear examples of informal conversation as well.