I pronomi personali soggetto

Personal pronouns are used instead of the name, and they assume the same logical-syntactical functions of the name in the sentence.
Subjective personal pronouns are:

Io - I
tu - you
lui, lei - he, she
(egli, ella) - he, she (formal, mainly in written texts)
(esso, essa) - it (rare, mainly in written texts)
noi - we
voi - you
loro - they
(essi, esse) - they (mainly in written texts)

The pronoun Lei is normally used as a polite form to address people (unknown or with a higher status):
Scusi, Lei parla italiano? - Excuse me, do you speak Italian?
Professor Rossi, Lei insegna italiano? - Do you teach Italian, Professor Rossi?

In some regions, the form Voi is still used with the same function, but it has almost completely disappeared from standard contemporary Italian.