يَا رَجُلُ
O man!
يَا فَتَى
O young man!
A vocative makes the person addressed identifiable in the communicative event, even where the person’s proper name is unknown. “O man” singles out the addressee, not every man.
Calling someone can also draw attention to a needed action. In this chapter the key point is how address identifies the hearer; the separate rhetorical purposes of vocative speech were treated under insha’.