다더라

I heard that, apparently

It relays something you heard rather than saw: apparently Koreans have a fridge just for kimchi, they say a kilo or two over sometimes gets waved through, apparently there is a strange disease going round in China. It welds the quoting piece onto the first-hand marker, so what you personally experienced was the telling, not the fact. It is a natural opener for gossip, which is what the lines about the homeroom teacher and about who gets on with whom are.

Register: casual; gossip and hearsay