-군

Contracted from 구나 (-guna); see there for more.

군 • (-gun)

1. I see; in the intimate style or in monologues, used to emphasize a new fact that the speaker has learned.

   그렇군. ― Geureot-gun. ― I see.

   결국 탈레반이 승리했군. ― Gyeolguk Talleban-i seungni-haet-gun. ― The Taliban has won in the end, I see.

   오늘도 또 후덥지근하겠군. ― Oneul-do tto hudeopjigeun-ha-get-gun. ― So today will be stuffy and hot, too.

• For verbs, the bare form cannot be used; it must be marked with tense/aspect, i.e. 는 (-neun-, present-tense suffix), 더 (-deo-, retrospective suffix), 었 (-eot-, past-tense suffix), 겠 (-get-, future-tense suffix). This is not the case for adjectives.