Exegesis:

epērōta de auton en logois hikanois ‘he questioned him with many words,’ durative imperfect, en has instrumental meaning.

autos de ouden apekrinato auto ‘but he gave him no answer.’ The aorist tense apekrinato implies that he did not answer one single word. autos indicates change of subject.

Translation:

One or more of the three pronouns, referring first to Herod, then twice to Jesus, may have to be specified.

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.