Six vowels do most of the work in Korean: ㅏ ㅓ ㅗ ㅜ ㅡ ㅣ. Every other vowel on the overview page is built from these, so getting their sounds precisely right pays off across the entire language. Four of the six map cleanly onto English. The other two — ㅓ and ㅡ — are where English speakers develop an accent that lasts for years, and they are the reason this page exists.
The four easy ones
| Letter | RR | Sound | Mouth position |
|---|---|---|---|
| ㅏ | a | [a] — the a in father | jaw dropped, tongue low and flat, lips relaxed |
| ㅗ | o | [o] — a pureo, as in Spanish no | lips rounded and steady, tongue mid-back |
| ㅜ | u | [u] — the oo in moon | lips tightly rounded and pushed forward, tongue high back |
| ㅣ | i | [i] — the ee in see | lips spread, tongue high and front |
아빠가 사과를 가져왔어요.
appaga sagwareul gajeowasseoyo
Dad brought some apples. (ㅏ everywhere)
이 구두 너무 예뻐요.
i gudu neomu yeppeoyo
These dress shoes are so pretty. (ㅜ in 구두, ㅣ in 이)
One warning even on the "easy" ones: Korean ㅗ is a pure vowel. English o in go is really [oʊ] — it glides toward an "oo" at the end. Korean ㅗ does not glide; the lips lock into their rounded shape and stay there. Say 오 (o) and freeze your lips — no drift toward "oh-oo."
ㅓ vs ㅗ: the rounding contrast
Here is the first killer. Revised Romanization spells these two "eo" and "o," and beginners, seeing both as some kind of "o," round their lips for both. That collapses them into one sound and wrecks whole words.
The truth is simple: ㅗ is rounded, ㅓ is not. ㅗ [o] pushes the lips into a tight circle. ㅓ [ʌ] keeps the lips relaxed and unrounded, jaw fairly open, tongue pulled back and low-mid — very close to the u in English cup or button. If your lips make a circle, you have said ㅗ, not ㅓ.
| ㅓ (unrounded) | ㅗ (rounded) |
|---|---|
| 선 seon — a line | 손 son — a hand |
| 벌 beol — a bee | 볼 bol — a cheek |
| 서다 seoda — to stand | 소다 soda — soda |
손에 선을 그렸어요.
sone seoneul geuryeosseoyo
I drew a line on my hand. (손 son vs 선 seon in one breath)
어머니가 시장에 가셨어요.
eomeoniga sijange gasyeosseoyo
Mother went to the market. (어 = unrounded ㅓ)
ㅡ: the vowel English does not have
The second killer is ㅡ [ɯ], romanized "eu." There is no English equivalent, and no amount of approximating with "uh" or "oo" will get you there. It is a high back unrounded vowel: the tongue is high and pulled back exactly as for ㅜ [u], but the lips are spread, not rounded.
Two reliable ways to find it:
- From ㅜ: say ㅜ [u] ("oo") and, without moving your tongue at all, pull your lips flat as if you were mildly smiling. The sound that comes out is ㅡ.
- From ㅣ: say ㅣ [i] ("ee"), keep your lips spread, and slide your tongue straight back. Same result.
It should sound tense and slightly "swallowed," never like the English schwa "uh."
크다
keuda
to be big (the 크 is ㅋ + ㅡ)
이 가방 진짜 커요.
i gabang jinjja keoyo
This bag is really big. (from 크다 → 커요; ㅡ drops to ㅓ here)
Notice how 크다 becomes 커요, not "keu-eoyo" — when the ㅡ stem meets an ending, the ㅡ drops out. That is the ㅡ-drop rule at work, but for now just hear the bare [ɯ] in the dictionary form 크다.
ㅡ vs ㅜ: don't round it
Because ㅡ and ㅜ share the same tongue position and differ only in the lips, rounding ㅡ turns it straight into ㅜ — another set of destroyed minimal pairs:
| ㅡ (unrounded) | ㅜ (rounded) |
|---|---|
| 글 geul — writing, text | 굴 gul — an oyster |
| 그 geu — that | 구 gu — nine (Sino-Korean) |
| 은 eun — silver | 운 un — luck |
그 글 누가 썼어요?
geu geul nuga sseosseoyo
Who wrote that piece of writing? (그, 글 = ㅡ; contrast 굴, 구)
All six in one place
| Letter | RR | IPA | Rounded? | Anchor word |
|---|---|---|---|---|
| ㅏ | a | [a] | no | 아빠 appa — dad |
| ㅓ | eo | [ʌ] | no | 어머니 eomeoni — mother |
| ㅗ | o | [o] | yes | 오이 o-i — cucumber |
| ㅜ | u | [u] | yes | 우유 uyu — milk |
| ㅡ | eu | [ɯ] | no | 크다 keuda — to be big |
| ㅣ | i | [i] | no | 아이 a-i — child |
우유 좀 사 주세요.
uyu jom sa juseyo
Please buy some milk. (우유 shows ㅜ, and the 요 hints at more vowels to come)
A note on length and Seoul speech
Older descriptions of Korean list vowel length (short vs. long ㅓ, for example) as meaningful. In modern Seoul speech this distinction has almost entirely disappeared, and you do not need to learn it — no one will misunderstand you for getting length "wrong," because native speakers under about fifty no longer make the contrast either. Focus your effort on quality (rounded vs. unrounded), which absolutely still distinguishes words.
Common Mistakes
1. Rounding ㅓ so it becomes ㅗ. The number-one English-speaker error. 서울 (Seoul) is Seo-ul, not So-ul; 넣다 (to put in) is not 노타.
✅ 서울에 살아요.
seoure sarayo
I live in Seoul. (서 = unrounded ㅓ)
Wrong: pronouncing 서울 with rounded lips as "소울."
2. Turning ㅡ into "uh" (a schwa). English speakers reach for the u in sofa. ㅡ is not a lazy schwa; it is a tense, high, back, spread vowel. Keep the tongue high and the lips flat.
✅ 그거 좀 크네요.
geugeo jom keuneyo
That's kind of big. (그, 크 = a firm [ɯ], not 'uh')
Wrong: saying 그 as an English "guh."
3. Rounding ㅡ into ㅜ. If your 글 (writing) sounds like 굴 (oyster), you rounded your lips. Spread them.
4. Adding an off-glide to ㅗ. Saying 오 as English "oh" (with the [ʊ] tail). Korean ㅗ is one steady rounded sound — lock the lips and hold.
✅ 오빠, 오이 좀 줘.
oppa, o-i jom jwo
Hey (older brother), pass me a cucumber. (오 = pure, glide-free ㅗ)
Wrong: gliding 오 toward "oh-oo."
5. Treating RR spelling as a pronunciation guide for ㅓ and ㅡ. The letters "eo" and "eu" are transliteration conventions, not phonetic recipes — do not read "eo" as English "ee-oh" or "eu" as "ee-you." Learn the sounds from the mouth positions above and treat the romanization purely as a label.
Key Takeaways
- Four vowels are easy: ㅏ [a], ㅗ [o] (pure, no glide), ㅜ [u], ㅣ [i].
- ㅓ is unrounded — closer to English cup than to o. Rounding it makes ㅗ. Keep the lips flat.
- ㅡ [ɯ] has no English match: high, back, spread lips. Find it from ㅜ (unround) or ㅣ (retract the tongue). It is not a schwa.
- Practice the two contrasts ㅓ/ㅗ and ㅡ/ㅜ as pairs; the difference lives entirely in whether the lips round.
Now practice Korean
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Start learning Korean→Related Topics
- The Vowels 모음: A Systematic SetTOPIK 1 — Korean's 21 vowel letters are not 21 unrelated shapes — they are a small basic core plus regular y-glide and w-glide expansions, and a letter's shape even tells you how it will stack inside the syllable block.
- The Y-Vowels ㅑㅕㅛㅠ (and ㅒㅖ)TOPIK 1 — The iotized vowels are the cleanest gift in the whole script: one extra stroke on a basic vowel adds a y-glide and nothing else, so if you know ㅓ you already know ㅕ.
- The W-Vowels ㅘㅝㅚㅟ (and ㅙㅞ)TOPIK 1 — The w-glide vowels look intimidating but decompose predictably: a rounded ㅗ or ㅜ contributes the 'w', the second vowel supplies the rest, and vowel harmony decides which pairs are even legal.
- Vowels That Merged: ㅐ=ㅔ, ㅙ=ㅚ=ㅞ, and ㅢTOPIK 1 — Some vowels are still written apart but now sound identical — the reassuring truth is that natives can't hear the difference either, so you memorize the spelling instead of straining your ear.
- Building a Syllable Block 음절TOPIK 1 — Korean letters are never written in a line — they cluster into square syllable blocks (음절), each an onset + vowel + optional final consonant; the real skill is decomposing a block back into its ordered letters, not memorizing it as a picture.