Classical Resultative: -온/운 (Past Modifier)

Generally, 있다 and 없다 do not take the -(으)ㄴ form to indicate a past action in the same way regular action verbs do. They are more akin to descriptive verbs in their adnominal usage. For 있다 and 없다, the present adnominal -는 is typically used to describe a current state: 있는 사람 (inneun saram) – "a person who exists/has," or 없는 시간 (eomneun sigan) – "time that doesn't exist/one doesn't have." To express a past event or state related to 있다/없다, you would usually use ~었던/았었던 (e.g., 있었던 일 – "a thing that happened/existed").

Passive and causative verbs, once formed, behave like regular action verbs. Therefore, they follow the exact same -(으)ㄴ conjugation rules to indicate a completed past passive or causative action.

• Passive: 열다 (to open) → 열리다 (to be opened) → 열린 문 (yeollin mun) – "the door that was opened." (ㄹ irregular for 열리다)
• Passive: 보이다 (to be seen/shown) → 보인 그림 (boin geurim) – "the picture that was shown." (from 보이다, vowel-ending stem)
• Causative: 먹다 (to eat) → 먹이다 (to feed) → 먹인 밥 (meogin bap) – "the rice that was fed." (from 먹이다, vowel-ending stem)

This is a crucial distinction:

• -(으)ㄴ (Past, Completed Action, Resultative): This form emphasizes that the action is fully completed, and the modified noun is now in a state resulting from that finished action. It presents the noun with a definitive past attribute.
• 읽은 책 (ilgeun chaek) – "the book that was read" (the reading is finished, the book has been read).
• 먹은 밥 (meogeun bap) – "the rice that was eaten" (the eating is done, the rice is gone).

• -던 (Retrospective, Habitual/Ongoing Past Action): This form indicates an action that was performed repeatedly, habitually, or was ongoing in the past, often with a nuance that the action might have been interrupted or that the speaker is recalling it. It implies an unfinished or continuous quality in the past, or a past habit.
• 읽던 책 (ikdeon chaek) – "the book one was reading" (implies it might still be unfinished) or "the book one used to read" (habitual).
• 먹던 밥 (meokdeon bap) – "the rice one was eating" (implies it was left unfinished) or "the rice one habitually ate."

This is a specific phonological anomaly. Most ㅂ irregular verbs (both action and descriptive) change ㅂ to ㅜ before a vowel suffix. However, 돕다 and 곱다 (to be beautiful/fine) are the primary exceptions, changing ㅂ to ㅗ instead, resulting in 도운 and 고운. This is an idiosyncratic rule that simply needs to be memorized. While 춥다 is a descriptive verb and 추운 signifies present coldness, 돕다 is an action verb, and 도운 signifies a past action of helping. The irregular change itself is consistent within 돕다/곱다.

-(으)ㄴ describes the modified noun, and the agent of the verb's action is often implied by context or explicitly stated. If the verb is transitive, the modified noun is typically the object of the action, and the agent is the subject that performed it: 선생님이 가르친 학생 (seonsaengnim-i gareuchin haksaeng) – "the student the teacher taught." If the verb is intransitive, the modified noun itself is the subject: 떨어진 나뭇잎 (tteoreojin namunnip) – "the leaf that fell."

No, absolutely not. While it might have historical roots or a more pronounced use in classical texts, -(으)ㄴ is a fundamental and frequently used grammatical structure in all registers of modern Korean—formal, informal, spoken, and written. The term "classical resultative" might highlight its succinctness and the definitive nature of the completed action it conveys, reminiscent of older linguistic patterns. However, its practical utility in contemporary communication is universal for forming concise and clear descriptive phrases. The politeness of a sentence is determined by its final verb ending, not by the adnominal modifier itself.