The -(으)ㅁ Nominalizer (written: 있음/없음)

If -기 names an activity and -는 것 is the everyday all-rounder, -(으)ㅁ is the nominalizer that crystallizes a verb or adjective into a fact, a state, or a finished result — and quietly stamps the sentence "written / formal." It is the ㅁ you see on notice boards (재고 없음, "out of stock"), the ㅁ frozen inside dozens of everyday nouns (믿음 "belief," 죽음 "death," 도움 "help"), and the ㅁ that formal Korean uses to say "the fact that…." Where -기 says doing, -(으)ㅁ says the established fact of it.

Forming -(으)ㅁ: the batchim rule (and the ㄹ trap)

The suffix has two shapes, chosen by the stem's final sound:

The ㄹ-stem row is the trap. An ㄹ-stem does not take -음; the ㅁ stacks directly onto the ㄹ to make the double batchim ㄻ. 살다 ("live") nominalizes to 삶 ("life"), never ×살음. This is the same ㄹ-stem behavior you meet across the verb system — the ㄹ stays put and the suffix attaches without 으.

삶 here is 살다 + ㅁ, "living / a life." (It happens to be spelled the same as 삶다 "to boil" nominalized — context always separates them.)

Notice-board style: 있음 · 없음

The most visible everyday use of -(으)ㅁ is the terse, telegraphic style of signs, forms, dictionary entries, and minutes. A full sentence would be 재고가 없습니다; the notice just writes the predicate as a nominal and stops:

This style is everywhere in Korean public life: 회의 있음 ("meeting scheduled"), 이상 없음 ("nothing abnormal"), 해당 없음 ("not applicable," on forms). It reads as neutral, official, and compact — you would never speak this way to a friend.

Lexicalized -(으)ㅁ nouns

Over centuries, -(으)ㅁ froze onto countless verbs and adjectives to mint permanent nouns. These are no longer felt as "nominalized verbs" — they are just vocabulary, but the ㅁ is the fossil of this very process:

Formal fact-complements: "the fact that…"

In formal and academic Korean, -(으)ㅁ nominalizes a whole clause into a fact that another verb can take as its object or subject — "the fact that X," "that X is the case." This is the written register's way of doing what speech handles with -다는 것. It typically appears with verbs like 알다 (know), 밝히다/밝혀지다 (reveal), 드러나다 (come to light), 확인하다 (confirm), and it usually rides in plain written style (한다체).

In 했음이, the whole clause 그가 거짓말을 했- ("he lied") is packaged by -음 into a fact and marked with 이 as the subject of 드러나다. This is the hallmark of reports, verdicts, academic prose, and headlines — the -(으)ㅁ signals overtly that you are in written register.

-기 (activity) vs. -(으)ㅁ (fact): a minimal pair

The cleanest way to feel what -(으)ㅁ contributes is to set it beside -기 on the same verb. 포기하다 ("give up") gives 포기하기 — the activity of giving up, something you might find hard or easy — versus 포기하지 않음 — the fact/state of not giving up, a nominal you can plant as a subject in a formal claim:

Swap in 포기하지 않는 것 and the sentence becomes ordinary spoken Korean; keep 않음 and it reads like an aphorism or a headline. Nothing about the meaning changed — only the register, and that is precisely the work -(으)ㅁ does.

The register signal is the whole point

-(으)ㅁ is not just an alternative to -는 것; choosing it announces formality. The identical thought splits by channel:

Use -(으)ㅁ deliberately, when you want the written-and-formal color — minutes, notices, academic writing, legal or official statements. Reach for it in casual speech and you sound like a court document. The spoken counterpart, the "-다는 것 / -다는" fact frame, is on the fact-that construction.

Common Mistakes

1. Using -(으)ㅁ in casual speech. In conversation, "I know that you're right" is a -는 것 / -다는 걸 sentence. -(으)ㅁ there sounds absurdly formal.

2. The ㄹ-stem trap: ×살음. ㄹ-stems take -ㄻ, not -음. 살다 → 삶, 알다 → 앎, 만들다 → 만듦.

3. Wrong batchim shape after a consonant stem. Consonant stems take -음, with the batchim liaising into it: 있다 → 있음 [이씀], 없다 → 없음 [업씀], 먹다 → 먹음. Don't write ×있슴 / ×없슴 (a common misspelling that mirrors the mispronunciation).

4. Forcing -(으)ㅁ where -기 owns the collocation. "Hard to learn" is the fixed activity frame 배우기(가) 어렵다, not ×배움이 어렵다. Keep -(으)ㅁ for facts/states, not for the ease/difficulty collocations that belong to -기.

Key Takeaways

• -(으)ㅁ nominalizes into a fact, state, or finished result, and its use signals written/formal register.
• Forms: vowel stem → -ㅁ (함, 큼, 꿈); consonant stem → -음 (먹음, 있음, 없음); ㄹ-stem → -ㄻ (삶, 앎, 만듦), never ×살음.
• It drives notice style (있음, 없음, 해당 없음), a huge stock of lexicalized nouns (믿음, 죽음, 도움, 웃음, 꿈), and formal fact-complements (…았음이 드러났다).
• In speech, prefer -는 것 / -다는 것; the difference between the three nominalizers is mapped on -기 vs. -(으)ㅁ vs. -는 것.