"How does it go?"
That question is a bit confusing, since "Come stai" means how are you, and "how does it go" is presumably pretty close to that
I agree. All three of these options ask the question "How are you?". Of course, "Come va" is informal, the others are more formal.
I think "come va" is expressing the informal "How's it going?" in English, or "Comment ca va?" in French.
But no one has responded yet to my question (below) regarding the literal translation of "how does it go?" which is not at all the same meaning.
Would one also use "come va?" when one wants to refer to how something functions? Would you not need a pronoun for the "it" in that case? If, for instance, one wants to say about a tune "how does it go?" would you need to put in "come lo va?"
Well if the English is "How does it go?" then yours is the most logical. e.g. "Does it need a battery?" My Italian-English dictionary gives:"How are you?" for all three. "come sta" formal, "come stai" informal. I also learned it on: http://ocw.mit.edu/courses/experimental-study-group/es-s41-speak-italian-with-your-mouth-full-spring-2012/ Speak-italian-with- your- mouth-full which is an Italian language class with recipes taught by an MIT professor. It's great.