-는-

• -ㄴ- (-n-) — see Usage notes

From Middle Korean -ᄂᆞ- (Yale: -no-), representing a merger of two independent Old Korean suffixes: 飛 (*-no-) and 臥 (*-nwu-). It is usually thought that 臥 (*-nwu-), despite the vowel shift, was closer to the present-tense meaning and that 飛 (*-no-) may have been a continuous aspect-marking suffix.^[1][2]

The reduplicated form 는 (-neun-) is used since the seventeenth century, except in certain contexts (see below) where the syncopated form -ㄴ (-n) is used after vowels.

• (SK Standard/Seoul) IPA^(key): [nɯn]
• Phonetic hangul: [는]

-는- • (-neun-)

1. A present tense-marking suffix for verbs; it attaches directly to the stem, including the honorific -으시- (-eusi-), and precedes another verbal suffix.

   Coordinate terms: -었- (-eot-, past-tense), -겠- (-get-, future)

   ‎먹- (meok-) + ‎-는- (-neun-) + ‎-다 (-da) → ‎먹는다 (meongneunda, “one eats”)

   ‎먹- (meok-) + ‎-는- (-neun-) + ‎-구나 (-guna) → ‎먹는구나 (meongneun'guna, “one is eating!”)

   ‎있- (it-) + ‎-는- (-neun-) + ‎-다 (-da) → ‎있는다 (inneunda, “one stays”)

• This suffix causes stem-final ㄹ (l) to drop out.
• This suffix takes the short form -ㄴ- (-n-) after vowels and before the formal non-polite ending -다 (-da). In all other cases, the full form is used: 안다 (anda), not *아는다 (*aneunda), but 아는가 (aneun'ga), not *안가 (*an'ga).