The sound system of Dai Lue is similar to that of other languages in the Southeast branch of the Tai language family.[1] A syllable has an initial consonant or an initial consonant cluster of either /kw/ or /xw/. There are no diphthongs, but there is vowel length contrast. A limited set of syllable-final consonants is possible. Each syllable has one of six possible tones. A word can have many syllables, and stress is always on the final syllable.

Tai languages are known as monosyllabic languages. Of the 13,000 words in this dictionary about 4,000 are true single-syllable words. About 60% of the words are compound words, and thus polysyllabic. Of the single-morpheme words about 20% have more than one syllable. Many of these are loan words from Indic languages, from Chinese, or from other sources.

Words of a single morpheme that have more than one syllable include loan words as well as words that are apparently of Tai origin.

ᦂᦱᦍᦱ            kaa¹jaa⁴             ‘body’      (Indic)

ᦀᦳᧄᦜᦳᧄ        ʔum¹lum¹          ‘round’        (Tai)

ᦀᦸᧅᦶᦀᧅ    ʔɔk²ʔæk²           ‘brain’      (Tai)

Many Dai Lue words start with a so-called minor syllable, which is a common feature of languages throughout Southeast Asia. Dai Lue minor syllables have the structure CV, with three cardinal vowels /a/, /i/ and /u/ as the only possible vowels, and /a/ being the most common. Minor syllables have no vowel length contrast, no final consonant, and no contrastive tone. The full range of initial consonants is found except for the clusters /kw/ and /xw/. Here are some examples of words with a minor syllable.

ᦏᦜᦲ tʰa-lii¹ ‘to declare’
ᦉᦵᦖᦲ sa-mɤɤ¹ ‘regular’
ᦉᦳᦟᦱ su-laa⁴ ‘liquor’
ᦔᦲᦰᦎᦲᦰ pi-tiʔ² ‘glad’
ᦔᦞᦎᦲᦰ pa-wa-tiʔ² ‘news’
ᦗᧃᦒᦓᧂ pan⁴-tʰa-naŋ⁴ ‘united’

Words with a minor syllable


As can be seen above, a word can have more than one minor syllable (‘news’), and minor syllables are not limited to the beginning of the word (‘united’). However, minor syllables never appear as the final syllable of a word.



Dai Lue has the nine vowels that are typical of Tai languages and common throughout Southeast Asia. There are no diphthongs.

i ɯ u
e ɤ o
æ a ɔ

Dai Lue vowels


Vowel length.[2] The vowel /a/ has short and long variants which appear in all environments. The short /a/ has a phonetic quality close to [ʌ], and the long vowel is pronounced [aa]. This length contrast is consistently produced and recognised by all speakers. The other eight vowels contrast for length only before a stop final (-p, -t, -k). In the phonemic transcription vowel length is written as a geminate.  For example, the long 'e' sound is written as /ee/ rather than /e:/.

For words with /-p, -t, -k/ finals the spelling convention for vowel length is not settled. For instance, both ᦢᦸᧅ bɔk² and ᦢᦸᧅᧈ bɔɔk² ‘to tell’ are commonly found, testifying to regional or personal variation in pronunciation. Words like these are listed following the most common spelling, but a note is made of the spelling variants.

All vowels can occur in an open syllable. Syllable final vowels are transcribed as long /VV/ (ᦵᦙ mee⁴ ‘wife’) except when there is final glottal closure when they are written as /Vʔ/ (ᦟᦰ laʔ⁵ ‘to abandon’).

The vowel /æ/. The vowel /æ/ is typically pronounced with a palatal onglide [ʲæ]. Thus ᦶᦜᧈ lææ² ‘yet’ is pronounced [lʲææ²], and ᦶᦃᧅᧈ xææk² ‘guest’ is pronounced [xʲææk²].

Dialect variation in vowels. For many speakers in Jinghong county the /u/ vowel is unrounded to /ɯ/ or /ɤ/ in certain words (e.g. ᦚᦳᧃᧈ fun² ‘dust’ is pronounced /fɯn²/ or /fɤn²/ by different speakers). These variants are recorded as alternate forms in the dictionary.



There are nineteen consonants in syllable initial position, some of which have allophones. The only consonant clusters are /kw/ and /xw/.

p t c k ʔ kw
x xw
b d
f s h
m n ŋ
w l j

Initial consonants in Dai Lue


In the coda of the main syllable there are only eight possible consonants.

‑p ‑t ‑k
‑m ‑n ‑ŋ
‑w ‑j

Final consonants in Dai Lue


Consonant variation. The sound transcribed as /c/ is pronounced as an alveo-palatal affricate [tɕ] before front vowels /i, e, æ/; and as an alveo-dental affricate [ts] before back and rounded vowels. Compare ᦈᦲᧂ ciŋ¹ ‘hard’ pronounced [tɕiŋ], versus ᦈᦳᧂ cuŋ¹ ‘to lead’ pronounced [tsuŋ]. The consonant /c/ never occurs at the end of a syllable.

The sound transcribed as /x/ is pronounced as an aspirated stop [x] by some speakers and a velar fricative [kʰ] by others. For many speakers these two forms vary freely and without the speaker’s awareness. Asked to repeat the word ᦆᦴ xuu⁴ ‘teacher’ several times, a speaker may alternate between [kʰuu] and [xuu]. The consonant cluster /xw/ has this same variation between [xw] and [kʰw]. The consonant /x/ never occurs at the end of a syllable.

The approximant /w/ varies in syllable initial position between [w] and [v]. Any one speaker typically is consistent, but two speakers will differ in their preferred pronunciation. In many areas, most speakers prefer [v]. At the end of a syllable it is always pronounced [w].

In the western part of the Dai Lue speech area, especially MengHai county, there is a tendency for words starting with /d/ to be pronounced as /l/, words starting with /b/ to become /m/, and words starting with /pʰ/ to become /f/. This results in merger of the pronunciation of many words, although they are still distinguished in the written form. In this dictionary the /d/ /b/ and /pʰ/ forms are distinguished from /l/ /m/ and /f/, as in eastern speech.

Many words with the initial cluster /kw/ are pronounced /k/ by some speakers. The /xw/ cluster appears to be more stable.

Syllabic /m̩/. The three words: ᦢᧁᧈ baw² ‘not’, ᦖᦱᧅ maak² ‘fruit’, and ᦢᦱᧁᧈ baaw² ‘young man’ are pronounced as shown in careful or isolated speech. In flowing or continuous speech these words are often pronounced simply as a syllabic /m̩/. Thus ᦢᧁᧈ ᦂᦲᧃ baw² kin¹ ‘not eat’ becomes m̩kin¹ ‘not eat’. Sometimes they reduce to nothing at all and the only trace of their presence may be a distorted tone on the following word (see the explanation of tone sandhi below). This reduction is more pronounced in some speakers than in others.[3]



In Tai languages each syllable has a distinctive tone, and tones are typically a combination of a certain pitch with a particular contour. Some tones are also typified by creaky phonation.

In Dai Lue there are six contrasting tones, marked in the transcription with superscript numbers 1-6. The diagram below shows Gedney’s 'tone box' which compares any Tai dialect with the proto-Tai forms (Gedney 1973:434). Proto-Tai had three tonal contrasts in ‘live’[4] syllables, labelled A, B, and C. In ‘dead’ syllables (D) there were two tones. In each of the Tai daughter languages these tones underwent a different series of splits and mergers based on the syllable-initial consonants, vowel length and coda. Thus each modern language has a different pattern of tone splits in this box.

Initials at the time of tonal splits voiceless and glottal sounds 1 2 3 2
voiced sounds 4 5 6 5

Gedney’s tone box showing Dai Lue tone splits


As is common in Tai languages, the pitch and contour of Dai Lue tones varies from village to village and region to region[5]. Some of the tones also have tone sandhi variants. In live syllables (columns A, B and C above) there are six tones, which have the following realisations.[6]

tone 1. A high level tone [in some places a mid-high rising tone].

ᦎᧁ              taw¹    ‘fireplace’


tone 2. A high rising tone, often ending very high.

ᦎᧁᧈ            taw²    ‘turtle’


tone 3. A low rising tone, often with some creakiness.

ᦎᧁᧉ            taw³    ‘come/go’


tone 4. A mid level tone [in some places a mid falling tone].

ᦑᧁ               taw⁴    ‘an edible seaweed’


tone 5. A higher-than-mid level tone [in some places a higher-than-mid falling tone].

ᦑᧁᧈ              taw⁵     ‘equal’


tone 6. A mid level [or mid falling] tone with creakiness.

ᦑᧁᧉ              taw⁶    ‘to support’


In dead syllables with a short vowel (in the D column above) tone 2 is higher than tone 5, although both are high tones.

tone 2 with a short vowel and a final stop. A high (often very high) tone.

ᦠᧅ             hak²    ‘to break’


tone 5 with a short vowel and a final stop. A high tone.

ᦣᧅ              hak⁵    ‘to love’


In dead syllables with a long vowel (the D column) the tones have the same pitch and contour as the tones in the B column.

tone 2 with a long vowel and a final stop. A high rising tone.

ᦠᦱᧅ           haak²  ‘really, very’


tone 5 with a long vowel and a final stop. A mid-high level tone.

ᦣᦱᧅ            haak⁵  ‘root’


Tone Sandhi. Tone sandhi is the influence of the tone of one word on the tone of a nearby word. Many Tai languages do not have sandhi, but Dai Lue is noted for some significant sandhi variation.[7]

Tone sandhi in Dai Lue operates between two syllables of a compound word or a phrase, and is clearly heard even in slow careful speech. In fast speech the sandhi effect will sometimes spread further, to a contiguous word across a phrase boundary.

The details of the sandhi differ from place to place within the Dai Lue speaking area.[8] The most dramatic example is the change in tones 4 and 6 when they follow a word with tones 2 or 3. A tone 4 word usually has a mid level (or in some places a mid falling) tone. Following a tone 2 or 3 it swoops up to a very high tone with a plunging drop. Seree (1975) records the normal tone 4 word, spoken in isolation, as falling from 170 to 120 hertz. A sandhi tone 4 moves up and then down from 150-310-190 hertz.

In each of these phrases the second word, which normally has a tone four, is influenced by sandhi.

ᦢᧁᧈ ᦙᦲ              baw² mii⁴S               ‘not have’

ᦶᦔᧆᧈ ᦞᧃ           pææt² wan⁴S           ‘eight days’

ᦠᦱᧉ ᦅᦳᧃ            haa³ kun⁴S               ‘five people’

There are a handful of words that are reduced in common pronunciation to a syllabic /m̩/, among which are ᦢᧁᧈ baw² ‘not’ and ᦖᦱᧅ maak² ‘fruit.’ Since these have tone 2 they cause tone sandhi in the following tone 4 syllable. In rapid speech these words are reduced totally, even the /m̩/ disappearing, and the only trace that they existed is that the following word has a sandhi tone. See these two sentences.

ᦃᦾᧉ ᦢᧁᧈ ᦙᦲ ᦃᧁᧉ. xɔj³ mii⁴S xaw³ I don’t have any food.
ᦃᦾᧉ ᦙᦲ ᦃᧁᧉ. xɔj³ mii⁴ xaw³ I have food.



[1] For studies of Dai Lue phonology see Fu (1956), Li (1964), Hartmann (1984), and Nanthariya (1984).

[2] See Hartmann (1976) for a discussion of vowel length in Dai languages.

[3] See Hartmann (1979) for more on syllabic /m̩/ in Dai Lue.

[4] In Tai linguistics ‘dead’ syllables are those with a stop final; ‘live’ syllables are open or have sonorant finals.

[5] See Kanita (2009) for variation of tone in Lue dialects of Thailand.

[6] See Seree (1975) for interesting spectrographs of the shape of Dai Lue tones in Chiang Kham, Thailand. These are typical of Dai Lue tones in other locations.

[7] See Gandour (1975) and Huebner (1976) for more on sandhi in Dai Lue.

[8] See Li (1964), Nanthariya (1984), and Seree (1975) for descriptions of how sandhi works out in different places.