In Italian, there are two pronouns that mean you in the singular. One is informal, to be used with a person with whom you are familiar, and the other is formal, which is to be used with a person of a status superior to yours or with a person you have just met. The informal form is tu and the formal form is Lei (note that it is only capitalized here to distinguish between the word for 'she'). The plural of tu is 'voi', and the plural of Lei is Loro. Knowledge of the difference between these the formal and informal forms is important because they take different verb forms.
In addition, especially in the south of Italy, you can also use the second person plural ('voi') when addressing an older person to whom you wish to show respect.
Signor Berti has just walked in. He says buon giorno to you. How do you ask him how he is? Come stai?
Your friend has gotten a new haircut. When telling them how much you like it, will you use the tu form or the Lei form? Tu
It is your first day of school and your teacher asks how you are. After responding, you wish to say 'and you?'. Which pronoun do you use? Sto bene.
Subject Pronouns and Essere / Pronomi personali soggetto e essere
Subject pronouns are used to show the subject of a sentence. In English subject pronouns are: I, you, he, she, it, we and they. Take a look at the following table which contains the corresponding pronouns in Italian.
Note that lei can mean either she or the formal, singular you, which is used both for masculine and feminine subjects. In written Italian Lei, written with a capital L, is used to represent a formal you. Note also that, unlike in English, io used for the first person in singular is not capitalized. Subject pronouns (io, tu etc.) are not always used in Italian because, unlike English, the grammatical person is indicated by the declension. Thus, while in English we would say I sing, in Italian we would normally use canto rather than io canto.
Essere (and also stare) is an equivalent of the verb to be in English. It is very irregular; the conjugation for the present indicative tense follows: