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 – 548.
For the cases with prepositions, alone or in composition, see §§ 597 – 599.