The Lao Language

Lao is a tonal language of the Kradai language family. It is spoken in Laos, as well as in the northeast of Thailand, where it is usually referred to as the Isan language. Lao is spoken by over 5 million people- 20 million if Isan is included.

History and Development

Lao is descended from ancient Tai languages spoken in what is now southern China and northern Vietnam. Around the 12th century, the Tai peoples moved south down the Mekong River valley, settling as far south as the Malay Peninsula. Tai speakers in what is now Laos pushed out or absorbed earlier groups of Mon-Khmer and Austronesian languages. Linguists believe that the ancient Tai language had only 3 tones, as opposed to the 5 or 6 in the various dialects of modern Lao.


The Lao language consists primarily of native Lao words. However, due to the influence of Buddhism, Pali has contributed numerous terms, especially those relating to religion. Due to their geographic proximity, Lao language has influenced Khmer language and Thai language and vice versa. To make oneself more polite, using pronouns (especially formal pronouns) is employed, as well as ending statements in dè ([dèː]) or deu ([dɤ]). Negative statements are made more polite by ending the statement in dok ([dɔːk]).

Phonology and Morphology


The Lao consonant inventory is shown below. Note that many consonants in Lao make a phonemic contrast between labialized (shown in parantheses) and plain versions.

  Labial Alveolar Palatal Velar Glottal
Voiced Plosive b d      
Voiceless Plosive p t c (cʷ) k (kʷ) ʔ (ʔʷ)
Aspirated Plosive tʰ (tʷʰ)   kʰ (kʷʰ)  
Fricative f s (sʷ)     h
Nasal m n ɲ ŋ (ŋʷ)  
Approximate   l (lʷ) j w  



Lao vowels are shown below. All vowels (including diphthongs) make a phonemic length distinction (long vowels are separate phonemes from short vowels). Diphthongs are all centering diphthongs with falling sonority.

Short monophthong phonemes

  Front Back
Close i ɯ • u
Close-mid e ɤ • o
Open-mid ɛ ɔ
Open ɑ  


Long monophthong phonemes

  Front Back
Close ɯː • uː
Close-mid ɤː • oː
Open-mid ɛː ɔː
Open ɑː  


Diphthong phonemes

  Closer component is front Closer component is back unrounded Closer component is back rounded
Short diphthongs ɯə
Long diphthongs iːə ɯːə uːə



Lao has the six tones shown below. In the tone contour column, 1 stands for low pitch, 3 for medium pitch, and 5 for high pitch. Glides are indicated by a dash.

Tone  Type Symbol on /e/


Tone contour

Rising ě 2-4 or 2-1-4
High level é 4
High falling ê 5-3
Mid level ē  3
Low level è  1
Low falling  ḙ  3-1



Lao syllables are of the form (C)V(C). Any consonant may appear in the onset, but the labialized consonants do not occur before rounded vowels. Only /p t k ʔ m n ŋ w j/ may appear in the coda. If the vowel in the nucleus is short, it must be followed by a consonant in the coda; /ʔ/ in the coda can be preceded only by a short vowel. Open syllables and syllables ending in one of the sonorants /m n ŋ w j/ take one of the six tones, syllables ending in /p t k/ take one of four tones, and syllables ending in /ʔ/ take one of only two tones. 
The majority of Lao words are monosyllabic, and are not inflected to reflect declension or verbal tense, making Lao an analytic language. Special particle words serve the purpose of prepositions and verb tenses in lieu of conjugations and declensions. Lao is a subject verb object (SVO) language, although the subject is often dropped. In contrast to Thai, Lao uses pronouns more frequently.


Original Contributor: Todd Greblo, Winter 2011

References and Resources