Lao phonology

Consonants
Many consonants in Lao make a phonemic contrast between labialized and plain versions. The complete inventory of Lao consonants is as shown in the table below:

Final consonants
All plosive sounds are unreleased in final position. Hence, final, , and sounds are pronounced as , , and  respectively.
 * The glottal stop appears at the end when no final follows a short vowel.

Vowels
All vowels (including diphthongs) make a phonemic length distinction. The vowels are as shown in the following table:

Diphthongs are all centering diphthongs with falling sonority:

Tones
Lao has six lexical tones.

Unchecked syllables
There are six phonemic tones in unchecked syllables, that is, in syllables ending in a vowel or other sonorant sound ( and ).

Checked syllables
The number of contrastive tones is reduced to four in checked syllables, that is, in syllables ending in an obstruent sound ( or the glottal stop ).

Syllables
Lao syllables are of the form (C)V(C), i.e. they consist of a vowel in the syllable nucleus, optionally preceded by a single consonant in the syllable onset and optionally followed by single consonant in the syllable coda. The only consonant clusters allowed are syllable initial clusters. Any consonant may appear in the onset, but the labialized consonants do not occur before rounded vowels.

Only may appear in the coda. If the vowel in the nucleus is short, it must be followed by a consonant in the coda; in the coda can be preceded only by a short vowel. Open syllables (i.e. those with no coda consonant) and syllables ending in one of the sonorants take one of the six tones, syllables ending in  take one of four tones, and syllables ending in  take one of only two tones.