I just want to share a bit of amusingness - the voice recognition function sometimes has a little trouble interpreting what I say. Sometimes it thinks I'm speaking English and so starts by putting some English words in the visual representation of what I say before settling on Italian. (And sometimes, indeed frequently, it doesn't get it quite right, though duolingo is pretty merciful in grading - I get a lot of "woot, you're almost right" because it records me as having left out words even though I've most definitely said them.) At any rate, today although I said "Tu leggi" it first thought I said "Jules and Jim." I'm sure my accent is bad, but I didn't think it was quite that bad!
From what I understand, "tu" is the singular form of you, whereas "voi" is the plural form (as in "you all"). Sometimes the "all" is left off, like how in English you could shorten "You all get it, right?" to "You get it, right?" while still addressing more than one person.
Just for clarity, as a comparison to English, would this be an imperative or declarative sentence? Whenever there is a "you + (verb) (direct object)" I never know for sure the type of the sentence unless there is context to infer the manner in which the sentence is being used.
Is this in past tense? Otherwise isn't the sentence a little wierd? Maybe it's just me but I can't think of a natrual way to use this sentence, it's almost a little bit "me Tarzan, you Jane". I would say "You are reading a book", maybe it translates the same in Italian?