Preach the word (κηρυξον τον λογον). First aorist active imperative of κηρυσσω. For "the word" used absolutely, see 1. Thessalonians 1:6; Galatians 6:6.

Be instant in season, out of season (επιστηθ ευκαιρως ακαιρως). Second aorist (ingressive) active imperative of εφιστημ (intransitive use), "take a stand," "stand upon it or up to it," "carry on," "stick to it." The Vulgate has "insta." The two adverbs are like a proverb or a play (pun) on the word καιρος. There are all sorts of seasons (καιρο), some difficult (χαλεπο, 2. Timothy 3:1), some easy (ευκαιρη, 1. Corinthians 16:12).

Reprove (ελεγξον). First aorist active imperative of ελεγχω. "Bring to proof." Ephesians 5:11.

Rebuke (επιτιμησον). First aorist active imperative of επιτιμαω, to give honour (or blame) to, to chide. Common in the Gospels (Luke 17:3).

Exhort (παρακαλεσον). First aorist active imperative of παρακαλεω, common Pauline word.