Nguyên âm và dấu — vowels and marks

Read this one first if you read nothing else. English vowel spelling is the least reliable part of English — "read/read", "though/tough", "bass/bass" — so you have spent your whole life guessing vowels from context. Vietnamese does not ask you to guess. Twelve vowel letters, twelve sounds, fixed.

The thing that trips everyone is the marks. Vietnamese puts two completely different kinds of mark on vowels, and telling them apart is the single most important reading skill in the language.

Shape marks — these six make new letters:

Tone marks — these five sit on top and change only the pitch: the grave à, the acute á, the hook ả, the tilde ã, and the dot underneath ạ. They are Book 4's job. Here, ignore them completely.

So ầ is one letter (â) carrying one tone mark (the grave). ữ is one letter (ư) carrying the tilde. Learn to see the letter underneath the tone and the whole page stops looking like noise.

Why this matters immediately: co, cô, and cơ are three different words with three different vowels and no tone on any of them. If you file the hat as "some kind of accent" you will read all three as "co" and be understood by nobody.

Anchors are General American unless marked. Two of these have no English equivalent at all and get a mouth recipe instead.

An accent note on o. If you are one of the many General American speakers for whom "cot" and "caught" sound identical, your "saw" vowel is unrounded and will come out as a, not o. Use the British "hot" instead, or just round your lips deliberately: o is the open one, ô is the closed one, and both have rounded lips. co (to shrink) and ca (a shift, to sing) are different words.

English long vowels are secretly diphthongs. Say "day" slowly and feel your tongue slide upward at the end: "day-ee". Say "go" and feel your lips close in: "go-oo". English does this automatically and you have never had to notice it.

Vietnamese ê and ô are those vowels with the slide removed. One steady position, held, then stop.

• ê — start to say "day" and freeze halfway. đêm (night), chê (to criticise), về (to return). The pair to feel it against is đem (to bring, open e) versus đêm (night, closed ê).
• ô — start to say "go" and freeze halfway. cô (aunt, Ms), ông (grandfather, sir), một (one).

Where British English differs: for ô, General American is the better anchor. British "go" starts from a schwa (ə-oo), so a British speaker copying their own "go" will land somewhere near ơu and be misheard. British speakers: start from a rounded "aw" and raise it, don't start from "uh".

If you say the diphthong anyway, natives will still understand — this one costs clarity, not meaning. Fix it when you have time; the errors below cost you words.

ư — the smiling "oo"

Close back vowel, unrounded. English has no unrounded back vowel at all.

The recipe that works:

1. Say "oo" as in "food". Notice your lips are pushed forward in a circle.
2. Hold the sound and the tongue exactly where they are.
3. Now spread your lips into a smile without moving your tongue.

The sound that comes out is ư. từ (word, from), thư (letter), chưa (not yet), nước (water, country), được (okay, to get). It is everywhere; get it early.

The alternative recipe, if smiling does not work: say "ee", then slide your tongue straight backwards without letting your lips do anything.

The failure mode to avoid: saying u instead. tu and từ are different words, and so are thu (autumn) and thư (letter).

ơ — the long "uh"

Mid-central, unrounded, and long. British and Irish English speakers already own this: it is the vowel in "bird", "nurse", "her" — just delete the r.

General American speakers have a problem: your "bird" vowel is r-coloured all the way through (the tongue is curled the entire time). Vietnamese ơ has no r in it anywhere. Get there by saying "uhhhh" — the sound you make when you are thinking — and holding it steady.

bơ (butter, avocado), chợ (market), cơm (cooked rice), mơ (to dream, apricot).

And â is ơ cut short

That is the whole difference. Same tongue position, same mouth, half the length. â never stands alone — it always has something after it.

• ơ long: tơ (silk) — â short: tây (west) has â before the y.
• dây (string) versus dơi (bat, the animal). Same consonant, same tone, and the only difference is that â is short and ơ is long.

ă is the short twin of a, exactly as â is the short twin of ơ. Like â, it never stands alone: ăn (to eat), mắt (eye), năm (year/five), chắc (surely).

Now the hidden part, and it is worth its own paragraph because it explains four spellings that otherwise look identical.

English will lie to you about all four. Your eye reads ay as the "ay" of "day" and au as the "au" of "haul" — both wrong. Vietnamese ay is closer to a clipped "eye", and au is closer to a clipped "ow" in "how".

Book 3 ([[endings-and-rhymes]]) drills these as a family, because they are endings, not vowels — but the reason they differ is here.

i and y are one sound. mì and mỳ (noodles) are two spellings of one word.

You will not go wrong reading them. Where the spelling does carry information:

• After a, the choice of i or y tells you the length of the a — ai long, ay short. That is the tai/tay rule above, and it is the only place the choice changes the sound.
• y is used alone in Sino-Vietnamese words (y tế health, ý idea, Mỹ America).
• y is used after the w-glide: quy, huy, tuy.
• i is the default everywhere else.

Native writers themselves disagree about some words (bác sĩ / bác sỹ doctor). Nobody minds.

Three vowel pairs are one sound that moves, not two separate vowels. English has nothing quite like them, but they are easy: start on the first vowel and let it relax into an "uh".

Two spellings, one sound. The open spelling (ia, ua, ưa) is used when nothing follows. The closed spelling (iê, uô, ươ) is used when anything follows — a consonant or a glide:

• mía (sugarcane) has nothing after it. miếng (a piece) has ng after it. Same vowel.
• mua (to buy) versus muốn (to want). Same vowel.
• mưa (rain) versus mười (ten). Same vowel.

yê and ya are the same sound again, spelled that way at the start of a syllable (yêu, yên) or after the w-glide (khuya late at night, uyên). One sound, four spellings — this is the least regular corner of Vietnamese orthography, and it is still far more regular than English "ee/ea/ie/ei/y".

In hoa (flower) the o is not a vowel — it is a w. hoa is "hwa". Same in quen (familiar, "kwen") and huy ("hwee").

The rule is mechanical:

Everywhere else o and u are real vowels. And note the trap: ua and uô are the sliding vowel above, not glide-plus-vowel. mua is "moo-uh", not "mwa".

The mouth-shape engine that animates the app's characters (vi_viseme.py) splits every syllable using exactly these rules — the same w-glide whitelist, the same three sliding vowels, the same shape marks kept while tone marks are stripped. If a syllable animates correctly on screen, the analysis in this book is the one that made it do so.

Southern vowels are close enough to Northern that you can ignore the differences while learning. The Southern differences that actually matter are in the endings (Book 3) and the tones (Book 4), not here.

Say each pair out loud. If they come out the same, the second one is wrong.

Next: [[endings-and-rhymes]] — how syllables finish, including the one habit that gives away every English speaker.