What is the difference between formal and informal speech in Italian?

When talking to friends or family you'd say come stai, which is a bit more informal than its formal counterpart come sta?

Like many other languages, Italian has a formal "you" (lei) and an informal "you" (tu). The verb changes accordingly, but we'll get to that!

If you're ever unsure in Italian whether you should use the formal of the informal approach: always go formal. Italians will certainly appreciate your politeness.