The Multilingualism of Ancient Palestine and the Multilingual JesusPast posts on the question of which languages Jesus spoke are here and links.
Within this public ministry, Jesus seems to have used Aramaic most often in more private settings with his disciples, and Greek almost always in more public settings, especially when there are crowds present.
See Also: The Multilingual Jesus and the Sociolinguistic World of the New Testament (Brill, 2015).
By Hughson T. Ong
McMaster Divinity College
Hamilton, ON, Canada
March 2016
I know I am behind on Bible and Interpretation. I will catch up as I find time.