Hangul Letter Names: Why ㄱ Is 기역, ㄷ Is 디귿, ㅅ Is 시옷

The Korean letter ㄱ is named 기역 (giyeok), not "기윽," and ㄷ is named 디귿 (digeut), not "디읃." The names are fixed in Article 4 of the Hangeul orthography rules, and the National Institute of Korean Language (NIKL) explains why three of the consonant names look irregular.

1. The official list

Article 4 says Hangul has 24 basic letters and sets their order and names. NIKL's Online Ganada quotes the article in full:

Consonants (14): ㄱ 기역, ㄴ 니은, ㄷ 디귿, ㄹ 리을, ㅁ 미음, ㅂ 비읍, ㅅ 시옷, ㅇ 이응, ㅈ 지읒, ㅊ 치읓, ㅋ 키읔, ㅌ 티읕, ㅍ 피읖, ㅎ 히읗.

Vowels (10): ㅏ 아, ㅑ 야, ㅓ 어, ㅕ 여, ㅗ 오, ㅛ 요, ㅜ 우, ㅠ 유, ㅡ 으, ㅣ 이.

Vowel names are just their sounds. Consonant names are the interesting part, because each is a two-syllable word that shows how the letter sounds at the start of a syllable and at the end.

2. The pattern behind the names

NIKL's explanation of Article 4 says the names of the letters and their order go back to Choe Sejin's Hunmong jahoe (1527). Choe wrote Hangul letter sounds in Chinese characters, pairing a character for the letter's sound at the start of a syllable with one for its sound at the end. For ㄱ he wrote 其役: 其 (gi) shows the starting sound and 役 (yeok) the final sound.

So most consonant names follow one template: add the vowel ㅣ before and ㅡ after, with the consonant in the first and last position.

3. Why ㄱ, ㄷ, ㅅ break the pattern

By that template the three names would be 기윽, 디읃 and 시읏. NIKL says these would be more consistent, but the traditional names were kept, citing the proverb "낫 놓고 기역 자도 모른다" ("can't even recognize the letter 기역 with a sickle in hand"). The reasons for the odd forms are:

• ㄱ → 기역. No Chinese character was read "윽," so Choe used the nearest sound, 役 (역).
• ㄷ → 디귿. No character was read "읃," so Choe wrote 末 (귿, meaning "end") and used only its meaning, "귿."
• ㅅ → 시옷. No character was read "읏," so Choe wrote 衣 (옷, meaning "clothes") and again used its meaning.

NIKL says the last two are marked as using the meaning of the character only. These are the names in use today.

4. The six added in 1933

Letters ㅈ ㅊ ㅋ ㅌ ㅍ ㅎ were not used as final consonants in Choe's time, so he gave them only the starting form: 지, 치, 키, 티, 피, 히. NIKL says the full names 지읒, 치읓, 키읔, 티읕, 피읖 and 히읗 were fixed in the 1933 Hangeul spelling unification proposal.

This answers a common question from the NIKL case collection: why isn't ㅋ "키역" or ㅌ "티귿"? The answer: 기역, 디귿 and 시옷 follow historical practice, while the rest are named by the rule that shows the letter's use as a starting and final consonant. Choe named only the letters from ㄱ to ㅇ, and the rest were named by the rule.

5. Double consonants and compound vowels

Article 4 also lists letters made by combining basic ones, with their names:

• Double consonants: ㄲ 쌍기역, ㄸ 쌍디귿, ㅃ 쌍비읍, ㅆ 쌍시옷, ㅉ 쌍지읒. 쌍 means "double."
• Vowels: ㅐ 애, ㅒ 얘, ㅔ 에, ㅖ 예, ㅘ 와, ㅙ 왜, ㅚ 외, ㅝ 워, ㅞ 웨, ㅟ 위, ㅢ 의.

NIKL's note on Article 4 says ㅙ and ㅞ combine three letters, while the others combine two.

6. Using the names

• To spell a word aloud, say each letter name: 한글 is 히읗 아 니은 / 기역 으 리을.
• To describe a final consonant, use the name: the final consonant of 밥 is 비읍 (ㅂ).
• When you see ㄸ in a word, you can say 쌍디귿.
• In a dictionary, the order is ㄱ ㄲ ㄴ ㄷ ㄸ ㄹ ㅁ ㅂ ㅃ ㅅ ㅆ ㅇ ㅈ ㅉ ㅊ ㅋ ㅌ ㅍ ㅎ. NIKL lists this as the dictionary order of consonants, and for vowels it gives ㅏ ㅐ ㅑ ㅒ ㅓ ㅔ ㅕ ㅖ ㅗ ㅘ ㅙ ㅚ ㅛ ㅜ ㅝ ㅞ ㅟ ㅠ ㅡ ㅢ ㅣ.

7. Key takeaways

• Article 4 of the Hangul orthography rules fixes the letters, order and names: 24 basic letters, 14 consonants and 10 vowels.
• Most consonant names pair a starting and a final sound, as in 니은 and 미음.
• ㄱ, ㄷ and ㅅ keep the traditional names 기역, 디귿 and 시옷 from Choe Sejin's 1527 Hunmong jahoe.
• The names of ㅈ ㅊ ㅋ ㅌ ㅍ ㅎ were fixed in 1933.
• Double consonants use 쌍: 쌍기역, 쌍디귿, 쌍비읍, 쌍시옷, 쌍지읒.