A strange sentence (in my opinion):
Σωκράτης: “Καταμανθάνω. Δοκεῖς γάρ μοι λέγειν τὴν πολιτικὴν τέχνην καὶ ὑπισχνεῖσθαι ποιεῖν ἄνδρας ἀγαθοὺς πολίτας.”
Πρωταγόρας: “Αὐτὸ μὲν οὖν τοῦτό ἐστιν τὸ ἐπάγγελμα, ὃ ἐπαγγέλλομαι.”
I cannot understand it, because of “οὖν” and “ὃ ἐπαγγέλλομαι”.
I find a translation: “That, Socrates, is exactly the profession which I make.” But does “ἐπάγγελμα” mean “job” or “vocation” here?
μὲν οὖν is a combo: “Well, yes."
And ὃ ἐπαγγέλλομαι amplifies τὸ ἐπάγγελμα, lit. “the promise that I promise,” cognate accusative.
It’s not a strange sentence in Greek.
“Why, yes! This is the very (αὐτὸ) promise that I make” or “That is precisely what I profess.”