G1620–ἐκτίθημι–ektithēmi

And when he was cast out, Pharaoh's daughter took him up, and nourished him for her own son.

ἐκτεθέντος ektethentos “When was being exposed”

But Peter rehearsed the matter from the beginning, and expounded it by order unto them, saying,

ἐξετίθετο exetitheto “he was explaining [it]”

And he began to speak boldly in the synagogue: whom when Aquila and Priscilla had heard, they took him unto them, and expounded unto him the way of God more perfectly.

ἐξέθεντο exethento “they expounded”

And when they had appointed him a day, there came many to him into his lodging; to whom he expounded and testified the kingdom of God, persuading them concerning Jesus, both out of the law of Moses, and out of the prophets, from morning till evening.

ἐξετίθετο exetitheto “he was expounding”