The sentence ending 거든 has an interactional function and can only be understood by analysing dialogues. This video presents an overview of 거든 and explains how it is used to manipulate the presentation of information in conversations by presenting a piece of new information as if it were presupposed.

This video is largely based on the paper below.
— Kim, A. Utterance-final -ketun in spoken Korean: A particle for managing information structure in discourse. (2015). Journal of Pragmatics, 88, 27–54.

Many thanks to the voice actors who appear in this video.
All mistakes are my own.