First question. Which of these “tag question” variations is most correct?
- You’re going, right John?
- You’re going, right, John?
- You’re going. Right, John?
(1) looks best, imo. (2) seems more proper, though. (3) seems way too emphatic.
Second question. What is the technical/grammatical name for the person being addressed in these sentences? “John” is a proper name, obviously, but how do you describe its function within the sentences above? “Target”? “Object”? “Addressee”? I assume there’s a more technical term for it.
In your examples, John is a noun of direct address, which is always set off by commas. While this rule is still valid in formal registers, one often sees very short sentences without a comma:
Welcome students. — instead of — Welcome, students.
That would suggest that
You’re going, right, John?
obeys the standard rule.
A semicolon might aid reading:
You’re going; right, John?