OET interlinear 3 YHN (3 JHN) 1:1

uW Translation Notes:

Note 1 topic: figures-of-speech / explicit

ὁ πρεσβύτερος

(Some words not found in SR-GNT: Ὁ πρεσβύτερος Γαΐῳ τῷ ἀγαπητῷ ὅν ἐγώ ἀγαπῶ ἐν ἀληθείᾳ)

John assumes that Gaius will know who he is when he calls himself The elder. If it would be helpful to your readers, you could make John’s name explicit. (See the Introduction to 3 John for a discussion of how to translate the term elder.) Alternate translation: [I, John the elder, am writing]

Note 2 topic: translate-names

Γαΐῳ

˱to˲_Gaius

Gaius is the name of a man, a fellow believer to whom John is writing this letter.

Note 3 topic: figures-of-speech / abstractnouns

ὃν ἐγὼ ἀγαπῶ ἐν ἀληθείᾳ

(Some words not found in SR-GNT: Ὁ πρεσβύτερος Γαΐῳ τῷ ἀγαπητῷ ὅν ἐγώ ἀγαπῶ ἐν ἀληθείᾳ)

If your language does not use an abstract noun for the idea of truth, you could express the same idea in another way. Alternate translation: [whom I love sincerely]