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Khmer Vowels: Dependent Signs and Why One Sign Has Two Sounds

Khmer vowels explained: each dependent vowel sign with its a-series and o-series reading, where the signs sit, the nasal and h marks, and independent vowels.

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Key takeaways

  • Most Khmer vowels are dependent signs that can only be written with a consonant, and they are read after it wherever they sit.
  • Wikipedia notes that most dependent vowels have two pronunciations, chosen by the series of the consonant.
  • The sign ា is [aː] after an a-series consonant and close to [iə] after an o-series one, as in កា and គា.
  • The nĭkkôhĕt ំ adds a final m and the reăhmŭkh ះ adds a final h, each changing the vowel too.
  • Independent vowels stand alone and appear in a small number of words, mostly of Indic origin.

Khmer vowels are where the script stops behaving like an alphabet. Most vowels are not letters at all but signs attached to a consonant, and most of those signs have two readings. Which reading you use depends on the consonant underneath, so learning a vowel means learning a pair of sounds. This guide sets out every dependent vowel sign with both values, then the diacritics that change them and the separate set of independent vowels. IPA values and UNGEGN romanisations follow Wikipedia's tables, which describe the Battambang-area pronunciation that Standard Khmer is based on.

Dependent signs: written around, read after

Wikipedia calls the dependent vowels srăk nĭssăy or srăk phsâm, "connecting vowels", and stresses two points. They can only be written in combination with a consonant or cluster, and the vowel is always pronounced after the consonant, even when part of the sign sits above, below or to the left of it. A sign like េ is written before the consonant but read after it; ោ wraps around both sides.

If no vowel sign is written, the consonant is usually read with its own inherent vowel, â for the a-series and ô for the o-series, which Khmer consonants and the two series explains letter by letter.

Why one sign carries two sounds

Wikipedia's Khmer language article traces the double readings to history. In Old Khmer, vowels after voiced consonants became breathy and diphthongised, so *kaa and *gaa drifted apart. When consonant voicing was lost, the vowel kept the difference; later the breathiness disappeared too, leaving modern [kaː] and [kiə]. That is the origin of the a-series and o-series, and it is why the sign ា reads differently after ក and គ.

The dependent vowels with both readings

Sign a-series IPA o-series IPA UNGEGN (a / o)
ា [aː] [iːə] a / éa
ិ [ə], [e] [ɨ], [i] ĕ / ĭ
ី [ej] [iː] ei / i
ឹ [ə] [ɨ] œ̆
ឺ [əː] [ɨː] œ
ុ [o] [u] ŏ / ŭ
ូ [oː] [uː] o / u
ួ [uə] [uə] uŏ
ើ [aə] [əː] aeu / eu
ឿ [ɨə] [ɨə] œă
ៀ [iə] [iə] iĕ
េ [eː] [eː] é
ែ [ae] [ɛː] ê
ៃ [ej] [aj] ai / ey
ោ [ao] [oː] aô / oŭ
ៅ [aɨ] [əɨ] au / ŏu

Four signs, ួ ឿ ៀ េ, have the same value in both series in this table, so they are the easiest to read. Wikipedia adds that pronunciations may differ in weak syllables and when a vowel is shortened by a diacritic, and that vowel quality varies widely in dialects such as Northern Khmer.

A worked example: reading five syllables

  1. កា: ក is a-series, so ា is [aː]: [kaː].
  2. គា: គ is o-series, so the same sign gives [kiə] in the Khmer language article's transcription.
  3. លា léa [liə]: ល is o-series, so ា takes its o-series reading, romanised éa.
  4. ត្រា tra [traː]: ត is a stop and a-series, and stops outrank the sonorant រ in a cluster, so the vowel is a-series [aː].
  5. ធំ thum: the circle above is the nĭkkôhĕt, and Wikipedia notes this word for "big" is pronounced [tʰom], or [tʰum] in some dialects.

Five syllables, one vowel sign appearing four times, and three different vowel sounds.

Nĭkkôhĕt, reăhmŭkh and bânták

Three diacritics change the vowel itself, and Wikipedia treats some combinations as vowels in their own right:

  • nĭkkôhĕt ំ nasalises the vowel with an added [m] and shortens long vowels: អំ is [ɑm] or [um], អុំ [om] or [um], អាំ [am] or [ŏəm].
  • reăhmŭkh ះ, "shining face", adds a final [h]: អះ is [ah] or [ĕəh].
  • bânták ់, a small stroke over the final consonant, shortens the vowel: inherent â becomes [ɑ], and ា in the a-series becomes short [a].

The fourth mark, yŭkôlpĭntŭ ៈ, a "pair of dots", shows a short vowel followed by a glottal stop.

Independent vowels: the ones that stand alone

Khmer also has independent vowels, sră pénh tuŏ, "complete vowels", which are written without a consonant. Wikipedia explains that they represent combinations of a vowel with an initial glottal stop or a liquid, appear in a small number of words that are mostly of Indic origin, and are used with some inconsistency. A handful are frequent: ឥឡូវ ĕlov "now", ឪពុក âupŭk "father", ឬ rœ "or" and ឮ lœ "hear". The Khmer language article adds that written words never begin with a regular vowel sign, only with a consonant or an independent vowel.

Practising the vowels in the app

Learn Cambodian, Speak Khmer teaches the vowels alongside consonants and numbers, with pronunciation help, romanised spelling and tracing practice, and lets you slow audio down for difficult sounds. It is one of our language-learning apps. If the stacked signs do not display correctly, see Khmer fonts on Android, and for the full writing system, the Khmer script explained.

Good to know

Frequently asked questions

Why do Khmer vowel signs have two pronunciations?
Because each consonant belongs to the a-series or o-series, and Wikipedia notes that most dependent vowel signs are read differently depending on that series. The split goes back to an old voicing contrast: vowels after voiced consonants became breathy and diphthongised, and the vowel difference outlived the voicing.
How is the Khmer vowel ា pronounced?
Wikipedia's script table gives [aː] after an a-series consonant and [iːə] after an o-series consonant; its Khmer language article transcribes the pair as [kaː] for កា and [kiə] for គា. UNGEGN romanises the two readings as a and éa.
What does the small circle above a Khmer letter mean?
That is the nĭkkôhĕt ំ. Wikipedia explains that it nasalises the inherent or dependent vowel with the addition of [m] and shortens long vowels. អំ, for example, is [ɑm] in the a-series and [um] in the o-series.
What are independent vowels in Khmer?
They are full vowel characters that stand without a consonant. Wikipedia says they are used in a small number of words, mostly of Indic origin, but a few common words use them, such as ឥឡូវ 'now', ឪពុក 'father' and ឬ 'or'.

Sources

  1. Khmer script (opens in a new tab)Wikipedia — accessed
  2. Khmer language (opens in a new tab)Wikipedia — accessed

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