-구먼 voices a realization, either to oneself or to the room, in a rustic and older-sounding register: 그렇구먼 역시 내 그럴 줄 알았다 'so that's it — I knew it.' Three lines here stack the Chungcheong -유 on top (똑똑히 봤구먼유 'I saw it with my own two eyes'), doubling the country flavour. Younger speakers wear it as a costume — playing an old man, a monk, a village elder.