-던

Equivalent to 더 (-deo-, retrospective suffix) +‎ ㄴ (-n, past/realis adnominal suffix), but it retains the older imperfective sense of 더 (-deo-), not its modern and more nuanced "retrospective" sense.

던 • (-deon)

1. The imperfective adnominal marker, used to make verbs and adjectives attribute nouns:
   1. After verb stems, indicates an action or state which was interrupted and hence not completed.

      내가 어제 먹던 케이크

      nae-ga eoje meokdeon keikeu

      the cake I was eating yesterday [but I did not eat all of it]

   2. After verb stems, indicates an event in the past which happened on a regular basis, but does not continue now.

      비가 오면 나가 걷곤 하던 대나무 숲길

      bi-ga omyeon naga geotgon hadeon daenamu sup-gil

      the lane in the bamboo grove I used to walk along when it rained

   3. After adjective stems, indicates a state which no longer exists.

      아름다웠던 내 고향

      areumdawotdeon nae gohyang

      my hometown which was once beautiful