Korean → Vietnamese
Vietnamese uses 35 sounds. You already own 18 of them from Korean. The other 17 are the work — and 16 of those are the dangerous kind: close enough to something you already say that you will substitute them without hearing yourself do it.
The silent swaps
Your mouth has something close enough to reach for. These survive for years precisely because they sound right to you — the fix is hearing the difference first, not trying harder.
the move: close, but not identical
Vietnamese: to eat · written "ă", "a (in ay, au)"
A SHORT a. Written ă on its own, but the a of tay and sáu is this vowel too — which is why tai/tay and sao/sáu are different words.
Your /a/ is the one in 나라 (country).
the move: velar → palatal
Vietnamese: hello / goodbye · written "ch", "tr (Hanoi)"
A stop made with the tongue body on the palate; there is no 'sh' after it. Close to Korean ㅈ but tighter and with no hiss. tr merges into it in Hanoi (the south says a retroflex /ʈ/).
Your /k/ is the one in 국 (soup).
the move: velar → palatal
Vietnamese: house · written "nh"
Spanish ñ. Also a final: anh, bánh.
Your /ŋ/ is the one in 강 (river).
the move: close, but not identical
Vietnamese: three; father · written "b"
Implosive: the larynx drops and air is drawn in as the lips open. A plain English b is understood, but sounds foreign. New for Korean speakers too — Korean ㅂ is neither voiced nor implosive.
Your /b/ is the one in 바보 (fool).
the move: close, but not identical
Vietnamese: to go · written "đ"
The barred đ is the ONLY d-sound in Vietnamese; the unbarred d is /z/ (or /j/ in the south).
Your /d/ is the one in 어디 (where).
the move: unrounded
Vietnamese: cooked rice; a meal · written "ơ"
Say /o/ and unround the lips — the same horn, same instruction. Close to Korean ㅓ (eo), and to American 'bird' with the r taken out.
Your /o/ is the one in 오늘 (today).
the move: unrounded
Vietnamese: to weigh; a kilo · written "â"
A SHORT ơ: cân is clipped, cơn is held. The vowel of American 'cut', or a short Korean ㅓ.
Your /o/ is the one in 오늘 (today).
the move: rounded
Vietnamese: to give; for · written "o"
Open o — the vowel of 'law' for an American who keeps caught apart from cot, shorter. Korean has nothing between ㅗ and ㅓ; this sits between them.
Your /ʌ/ is the one in 서울 (Seoul).
the move: alveolar → labiodental
Vietnamese: phở (noodle soup) · written "ph"
The missionaries' spelling of /f/. There is no letter f in native words.
Your /s/ is the one in 사람 (person).
the move: voiced
Vietnamese: yes (polite) · written "d", "gi", "r (Hanoi)"
Three spellings, one Hanoi sound. The south says d and gi as /j/ and r as /ʐ/ or a trill, and keeps all three apart in writing.
Your /s/ is the one in 사람 (person).
the move: open → open-mid
Vietnamese: mother · written "e"
Open e — French è, the e of American 'bed'. Korean ㅐ as it was before Seoul merged it into ㅔ: Vietnamese still keeps the two apart, so mẹ 'mother' and mê 'to be entranced' are different words.
Your /a/ is the one in 나라 (country).
the move: alveolo-palatal → velar
Vietnamese: no; not; zero · written "kh"
German ach, Spanish j — or Korean ㅎ in front of ㅡ (흐), which comes close. không is the word you will say most.
Your /ɕ/ is the one in 시간 (time).
the move: plosive → fricative
Vietnamese: chicken · written "g", "gh"
A voiced fricative, like Spanish g between vowels — softer than English g. gh before e/ê/i.
Your /ɡ/ is the one in 고기 (meat).
the move: it glides, yours would hold still
Vietnamese: money · written "ia", "iê", "ya", "yê"
One diphthong, spelled ia when nothing follows (kia) and iê when a consonant does (tiền).
Your /i/ is the one in 이 (this; two; tooth).
the move: it glides, yours would hold still
Vietnamese: rain · written "ưa", "ươ"
ưa when final (mưa), ươ before a consonant (nước, người).
Your /ɯ/ is the one in 그 (that; he).
Words you may say identically
Two or more Vietnamese sounds landing on one sound of yours. Until the ear separates them, the mouth cannot — which is what the ear trainer is for.
Genuinely new
Nothing in Korean sits close to these. They sound foreign in your mouth — which is the good news: you can hear that you are not saying them yet.
happy, fun
Hanoi /v/; the south says /j/, so vui sounds like 'yui'.
Closest thing you own: — but alveolar → labiodental, voiced.
Rhythm and pitch
The layer spelling never records, and the one that makes a correct sentence still sound foreign.
| Korean | Vietnamese | |
|---|---|---|
| Rhythm | Syllable-timed, phrase melody | Syllable-timed, one tone per syllable |
| Stress | None at word level. No syllable is reduced and no vowel becomes a schwa; every syllable is said in full. What an English ear hears as stress is the phrase-initial rise. | No lexical stress. Every syllable carries its own tone and its own full vowel, and none is reduced. What sounds like stress to an English ear is a syllable holding its tone longer or louder for emphasis, and grammatical words (đã, sẽ, được) being said lighter and faster than content words. |
| Pitch | Not tonal, and not a pitch-accent language either in the standard: Seoul Korean gives its pitch to the PHRASE, not the word. Each accentual phrase rises over its first two syllables and falls at the end (low-high … high-low), and the very first syllable starts higher after an aspirated or tense consonant than after a plain one — which is how listeners tell 달 from 탈 at the start of a phrase. Questions rise at the end, as in English. The Busan and Daegu dialects DO have lexical pitch accent (가지 is 'branch' or 'aubergine' by pitch there), which is why southerners sound sing-song to Seoul. | lexical tone — pitch changes the word |
What you have that Vietnamese doesn't
16 sounds with no job in Vietnamese. They are not mistakes — but they are where an accent leaks in, because a sound you own is easy to use when a hard one is due.
The honest caveat
This is a prediction from the shape of two sound systems, not a recording of you. It says what your inventory makes likely — it cannot know that your Korean has a regional variety that already owns one of these, or that you learned Vietnamese from someone whose accent you copied. A teacher listening to you beats it. Use it to know what to listen for.
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