Do you use lisez here instead of lis because vous is the formal for you?
"lisez" is the correct conjugation for "vous", both the polite one and the plural one.
could also be constructed as "you are reading the letter"
I knew that this sentence should be "Vous lisez la lettre", but Duolingo did not give me the option "lisez" in this sentence.
Can this be used in the context of "I want you to read it"..? You read the letter...because I'm asking you to. Or is it just observational? Just wondering!
the context you point to is when you use the imperative voice (order, command, advice...)
"vous lisez la lettre" is a statement, in indicative
"lisez la lettre !" is an order, in imperative
Excellent reply as always, thanks!