Vietnamese is a tonal, monosyllabic-leaning, phonemic language. Its phonology is characterized by:

A rich vowel system (including many diphthongs/triphthongs)

A moderate consonant inventory

Six tones (Northern Vietnamese — Hà Nội standard)

A simple syllable structure (mostly C V (C))

Below is a concise but complete introduction.

1. Vowels

Vietnamese has 12 basic vowel qualities plus many diphthongs/triphthongs.

Vowel length is not phonemic; however, quality contrasts matter a lot.

a /a/ Low central, open

ă /ă/ Short /a/; more centralized

â /ɘ/ Mid-central, tense (schwa-like but higher)

e /ɛ/ Open-mid front

ê /e/ Close-mid front

i /i/ High front

o /ɔ/ Open-mid back rounded

ô /o/ Close-mid back rounded

ơ /ɤ/ Mid-back, unrounded

u /u/ High back rounded

ư /ɯ/ High back unrounded (unique Southeast Asian vowel)

y /i/ Same as “i”

2. Diphthongs

/iə/ ia

/ɯə/ ưa

/uə/ ua

3. Consonants

Vietnamese has about 20–22 consonants, depending on dialect.

b /ɓ/ Implosive “b”

đ /ɗ/ Implosive “d”

d /z/ “z” sound in the North (in the South: /j/)

gi /z/ Same as d (North)

r /z/ or /ɹ/ Often /z/ in the North

v /v/ Sometimes /j/ in the South

g/gh /ɣ/ Voiced velar fricative

kh /x/ Voiceless velar fricative

c/k/q /k/ Unreleased at end of syllable

ph /f/

th /tʰ/ Aspirated

tr /t͡ʂ/ Retroflex affricate

ch /t͡ɕ/ Palatal affricate

nh /ɲ/ Palatal nasal

ng/ngh /ŋ/ Velar nasal

l /l/

m /m/

n /n/

t /t/

h /h/

4. Final Consonants

Vietnamese final consonants are limited; no clusters.

Nasals: /m n ŋ/

Stops (unreleased): /p t k/

Semivowels: /j w/ (coded orthographically as i/y, u/o)

Important: final stops are completely unreleased:

bác → [baːk̚] (k̚ = unreleased)

5. Tones

Northern Vietnamese (Hanoi) has 6 tones, all phonemic.

Level (none) mid level 33 neutral

Sắc ´ high rising 35 sharp rise

Huyền ` low falling 21 breathy

Hỏi ̉ dipping 214 creaky-dipping

Ngã ̃ glottal rise 214ʔ strong glottalization

Nặng . low glottal 21ʔ heavy glottal stop at end

Tones are crucial for meaning.