-을

• -ㄹ (-l) (after a vowel)
• -를 (-reul) (rare, formal, after a vowel)

• IPA^(key): [ɨɭ]

-을 (-eul)

1. indicates the direct object of a verb

   시리레 ᄀᆞ를 담으라.

   sirire gawreu-l dam-eura

   Put the flour into the steamer.

• -을 (-eul) is used after a word ending with a consonant. If the preceding word ends in a vowel, -ㄹ (-l) is used instead.

• (subject marker) -이 (-i)
• (topic marker) -은 (-eun)

• (SK Standard/Seoul) IPA^(key): [ɯɭ]
• Phonetic hangul: [을]

From Middle Korean -을〮/-ᄋᆞᆯ〮 (Yale: -úl/ól), from Old Korean 乙 (*-ur) in the early second millennium, from even earlier 肹 in the late first millennium. The post-vocalic form 를 (-reul) is probably formed by pre-Middle Korean reduplication, with the original form ㄹ (-l) now relegated to colloquial speech.

• 를 (-reul) – after vowels
• ㄹ (-l) – after vowels, colloquial

을 • (-eul)

1. The accusative particle, indicating the direct object of a verb.

   너를 사랑했어. ― Neo-reul sarang-haesseo. ― I loved you.

   사람을 살리다 ― saram-eul sallida ― to save a person

   꽃을 보다 ― kkoch-eul boda ― to see a flower

   부산을 가다 ― busan-eul gada ― to go to Busan

   공부를 하다 ― gongbu-reul hada ― to study

   컨닝을 하다 ― keonning-'eul hada ― to cheat on a test

2. In "long negation" constructions with 지 (-ji), attaches to the negated verb to add emphasis.

   아기는 울지를 않았다. ― Agi-neun ulji-reul anatda. ― The baby did not cry.

   배구 선수는 공을 놓지지를 않았다. ― Baegu seonsu-neun gong-'eul nochiji-reul anatda. ― The volleyball player did not lose the ball.

• Note that Korean verbal transitivity can differ from the English equivalent. In particular, verbs of motion can take direct objects, and most compound verbs with 하다 (hada) function as transitive verbs where the meaningful element is a noun which is the direct object of 하다 (hada).
• Korean case-marking particles can be omitted if the case is obvious from context; in such cases, the particle has an emphatic sense.
• 를 (-reul) can occur after the locative particle 에 (-e) and the instrumental particle 으로 (-euro).

From Middle Korean -으ᇙ/ᄋᆞᇙ (Yale: -ulq/olq), from Old Korean 尸 (*-(u)lq).

In Old Korean, a (perhaps the) primary function of this suffix was to form verbal gerunds that could function as nouns, much as English -ing-forms serve as both independent nouns and to attribute nouns adjectivally; this nominalizing usage was only vestigial in Middle Korean and is wholly defunct today.

• ㄹ (-l) – after vowels

을 • (-eul)

1. A verbal and adjectival irrealis adnominal suffix; generally equivalent to English "that [one] will" or "who [one] will", but not always with a future meaning; indicates the future intention of the subject, the inference of the subject about an event (whether past, present, or future), a general timeless fact, something that ought to be done, etc.

   Coordinate term: 은 (-eun, realist/past adnominal suffix)

   파티에 올 사람들

   pati-e ol saramdeul

   the people who are going to come to the party

   친구에게 줄 선물

   chingu-ege jul seonmul

   the gift that I will give to my friend

   죽일 놈

   jugil nom

   the bastard who ought to be killed

   (literally, “the bastard who [people] ought to kill”)

   비가 올 때 이 거리는 잠긴다.

   Bi-ga ol ttae i geori-neun jamginda.

   At times when it rains, this street is submerged.

   목발은 못 걸을 때 사용한다.

   Mokbar-eun mot georeul ttae sayonghanda.

   You use crutches when you can't walk.

   차가웠을 물

   chagawosseul mul

   water which should have been cold; water which I predict was cold

• Compare the realis/irrealis contrast:

  차가웠던 물

  chagawot-deon mul

  water which was [factually] cold

  차가웠을 물

  chagawoss-eul mul

  water which should have been cold; water which I predict was cold