Complete sentences are simple, compound, or complex. In the simple sentence subject and predicate occur only once. A compound sentence ( cross2162) consists of two or more simple sentences coördinated:
τῇ δ' ὑστεραίᾳ ἐπορεύοντο διὰ τοῦ πεδίου, καὶ Τισσαφέρνης εἵπετο
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].