502. A noun (or pronoun) in the same case with another, and denoting the same person or thing, is an appositive if added directly, a predicate if added by means of a verb. Both appositive and predicate noun may be in any case, according to the construction of the primary noun.
Αὐδῶμαι δὲ παῖς Ἀχιλλέως, Nεοπτόλεμος.
I am called the son of Achilles, Neoptolemos.
Soph. Philoctetes 240-241
Here Neoptolemos is an appositive to παῖς, which is a predicate noun, agreeing with the understood subject of αὐδῶμαι. For special idioms of predication in Greek see 545, 546, 547, 548.
For the cases with prepositions, alone or in composition, see 597, 598, 599.