A.T. Robertson Commentary Luke 15:29

"But he answered and said to his father, Lo, these many years do I serve thee, and I never transgressed a commandment of thine; and [yet] thou never gavest me a kid, that I might make merry with my friends:" — Luke 15:29 (ASV)

Do I serve thee (δουλευω σο). Progressive present tense of this old verb from δουλος (slave) which the elder son uses to picture his virtual slavery in staying at home and perhaps with longings to follow the younger son (Robertson, Grammar, p. 879).

Transgressed (παρηλθον). Second aorist active indicative of παρερχομα, to pass by. Not even once (aorist) in contrast with so many years of service (linear present).

A kid (εριφον). Some MSS. have εριφιον, diminutive, a little kid. So margin of Westcott and Hort. B has it also in Mt 25:32, the only other N.T. passage where the word occurs.

That I might make merry (ινα ευφρανθω). Final clause, first aorist passive subjunctive of the same verb used in verses 23,25.