Tu vs. Voi
Im a little confused on when to use both of these. Duo says they both mean you but whats the difference? Is one of them formal and the other one isn't? Please help!
There are also formal versions of you "Lei" singular and "Loro" plural, not to be confused with "lei" which is she and "loro" which is they. Capitalization is the difference! So "tu", singular, and "voi", plural, are the familiar versions of you.
http://italian.about.com/library/fare/blfare113a.htm (Italian Subject Pronouns)