Lao (Vientiane)

Lao is the main language of Laos, and is also spoken across the border in northeastern Thailand, where it is known as Isan.

There are a couple varieties of Lao-Isan, of which the Vientiane dialect is the most commonly viewed as a prestige accent, so the Lexx Rom tones will be based on this pronunciation.

The Lao script is based on the Old Khmer script, which is based on the Indic Brahmic script model that is widespread across South and Southeast Asia. The shapes of the letters are very similar to their corresponding letters in Thai script. Therefore, when learning Lao script as a non-native, even if never having studied an Indic script before, it is helpful to learn some of the basic principles in order to understand the underlying logic and rationale beneath its structure. Additionally, the Lao tonal system developed as part of the East Asian Sinospheric tone system Sprachbund, so it is helpful to learn some principles of how these tonal systems work in order to understand how Lao tone marks interplay with the Indic-based script.

In the following chart of initial consonants, "Ancestral Lao" shows what sound the letter would have represented in earlier forms of the language, and "Ancestral Tone Class" shows what tone class the letter belongs to based on its original phonetic value.

Compared to Thai orthography, modern Lao orthography has underwent a massive simplification, so a lot of letters that Thai still uses

Initials

Some dialects of Lao spirantize /kʰ/ into /x/.

/r/ has merged into /l/ or /h/ in modern Lao; words that merged to /h/ are spelled with ຮ, and words that merged to /l/ are spelled with ລ. However, there are also modern loanwords in Lao that have /r/, and so this letter is used for the /r/ sound for in these modern loanwords. There are also some writers who prefer to etymologically use ຣ to indicate the /l/ in words where it was etymologically originally /r/ such as in Sanskrit/Pali loanwords, but this is not officially sanctioned in the modern orthography.

The pronunciation of ວ can vary between /ʋ/ and /w/, and although there is a tendency towards /ʋ/ in the speech of many from Vientiane, for consistency with other Lao dialects as well as other Tai languages, it is transcribed as <w> in Lexx Rom.

The three tone classes in Thai are High, Middle, and Low, based on the ancestral sound of each letter.

Voiceless aspirated plosives/affricate (ຂ kʰ, ຖ tʰ, ຜ pʰ) and voiceless fricatives (ສ s, ຝ f, ຫ h) comprise the High tone class.

Unaspirated voiceless plosives/affricate (ກ k, ຈ tʃ, ຕ t, ປ p) and glottalized initials (ດ ɗ, ບ ɓ, ຢ ʔj, ອ ʔ) comprise the Middle tone class.

Voiced plosives/affricate (ຄ ɡ, ຊ dʒ, ທ d, ພ b), voiced fricatives (ซ z, ຟ v, ຮ ɦ), and sonorants (ງ ŋ, ຍ ɲ, ณ ɳ, ນ n, ມ m, ຣ r, ລ l, ວ w) comprise the Low tone class.

ຢ is a special case because it is a Middle tone class letter despite being a sonorant /j/. This is because technically this letter corresponds to ancestral glottalized /ˀj/, whereas the true ancestral voiced /j/ merged into ຍ ɲ. When the -j coda is written as part of a compound rime, the ຍ ɲ letter is used, rather than ຢ (detailed in the rime section later).

The sonorant letters can also become High tone class if they have the letter ຫ h appended in front of them, as ຫງ ຫຍ ຫນ ຫມ ຫລ ຫວ. There are also some special ligature characters for some of these than can be used: ໜ (ຫນ), ໝ (ຫມ), and ຫຼ (ຫລ).

The names High, Middle, and Low refer to areal pattern in East Asia of voiced initials triggering lower tones for their syllables compared to the syllables with voiceless initials, which is a cross-linguistically attested natural acoustic tendency due to the lower formant frequency caused by the voicing. However, this no longer reflects the modern Lao tone reflexes for these letters, due to language change over time.

As seen in the chart above by comparing the ancestral sounds to the modern Lao sounds, voiced plosives/fricatives devoiced and became aspirated.

Final Codas

These six codas -k, -ng, -t, -n, -p, -m are a common set of final codas in the East Asia region. Note that the letter used as the default to write finals -t and -p are actually the letters d and b.

Vowels and Rimes

Lao has nine basic vowels, all of which can occur as short or long. The representation of the vowel in the script is sometimes different if there is a final coda consonant coming after it.

Basic Vowels

/ɛ(ː)/ is quite low, close to /æ(ː)/. Short /a/ can approach /ɐ/, though not quite exactly reaching the position of Cantonese /ɐ/.

Short vowels without any coda consonant ending actually carry a light glottal stop coda /ʔ/, though it is not always fully pronounced if not in word-final position, and is sometimes omitted in rapid speech as well. This glottal coda means that these short vowel rimes actually count as checked syllables for the purposes of tonal behavior (discussed in the next section). This glottal stop coda is not indicated in Lexx Rom transcription.

Compound Rimes

The short falling diphthongs /iə, uə, ɯə/ are marginal to the phonological system, so the default Lexx Rom <ia, ua, ưa> indicate the full length diphthongs /iːə, uːə, ɯːə/.

The letter ຽ was formerly also used as an alternate letter for ຍ in any non-intial position, but this is not part of the modern official orthography.

The mark ໃ◌ indicates a different sound /aɰ/, still found in other Lao dialects as well as Tai languages such as Shan, but in Vientiane Lao, this sound has merged into /aj/, though the spelling still reflects it etymologically. Likewise, a few rare words with /aj/ spelled ◌ັຍ (generally due to etymological transliteration of Indic loans) must have the spelling memorized.

Tones

Vientiane Lao has five contrastive tones, though the script does not directly indicate them in a one-to-one corresponding manner. Tones in Lao are indicated through an intricate interaction between initial consonant tone class (refer to the initials section of this guide) and tone mark. The five tones are as follows:

Tones

The commonly used tone names reflect a naming convention in Thai and Lao that follows the general tone contour pattern, but it needs to be pointed out that technically the high tone is also a rising tone contour, and the low tone is also a falling tone contour, so you may sometimes see materials use wordier names such as "high falling" vs. "low falling" vs. "high rising" vs. "low rising", and this is also complicated by the differences between tone contours across different Lao dialects as well as free variation between different speakers, for example the <âa> is technically a peaking tone ˦˥˧ for many speakers, though it has also been described as a high falling tone, and the (low) rising tone can actually have a dipping contour before rising.

As mentioned previously, there are three tone classes in Lao, High tone class, Middle tone class, and Low tone class, and the tone of a syllable will depend on which tone class the initial belongs to. The easiest way to conceptualize how to calculate Vientiane Lao tones is by remembering patterns for the High tone class and the Low tone class, because in Vientiane Lao the tone for the Middle tone class will always pattern with either the High or Low tone class, rather than having its own set of tones.

In the High Tone Class:

The default tone category (no tone mark) is <ǎa>.
With tone mark one (◌່ ), the tone becomes mid-flat tone <aa>.
With tone mark two (◌້ ), the tone becomes low tone <a̩a>.

If the syllable has a checked coda, one must check whether it is a short or long rime.
For short rime checked coda syllables, the tone becomes high rising <á>.
For long rime checked coda syllables, the tone becomes low tone <a̩a>.

In the Low Tone Class:

The default tone category (no tone mark) is <áa>.
With tone mark one (◌່ ), the tone becomes mid-flat tone <aa> (same as in the High Tone Class).
With tone mark two (◌້ ), the tone becomes high falling tone <âa>.

If the syllable has a checked coda, one must check whether it is a short or long rime.
For short rime checked coda syllables, the tone becomes mid-flat tone <a>.
For long rime checked coda syllables, the tone becomes high falling <âa>.

In the Middle Tone Class:

In Vientiane Lao, all tonal behavior for the Middle tone class will align with either of the High or Low tone classes, so learners can just memorize which category causes it to align with either High or Low.

The default tone category (no tone mark) is <ǎa> ( = High tone class).
With tone mark one (◌່ ), the tone becomes mid-flat tone <aa> ( = High & Low tone classes).
With tone mark two (◌້ ), the tone becomes high falling tone <âa> ( = Low tone class).

If the syllable has a checked coda, one must check whether it is a short or long rime.
For short rime checked coda syllables, the tone becomes mid-rising tone <á> ( = High tone class).
For long rime checked coda syllables, the tone becomes high falling <âa> ( = Low tone class).

The only consistent tone mark across all Vientiane Lao syllables is tone mark one (◌່ ), which indicates mid-flat tone regardless of tone class.

There are also two additional tone marks, tone mark 3 (◌໊ ) and tone mark 4 (◌໋​ ), which are very rarely used in Lao. If seen, these overtly indicate high rising tone <áa> and low rising tone <ǎa> respectively, as they do in Thai.

As mentioned earlier, there are many different dialects and accents of Lao, and even within Vientiane Lao, you will encounter variation between speakers, so for example the default tone for Middle tone class for some speakers is a sixth tone- a low flat tone /˩/ (a̠a). But in general, the tone values as given above are a good reference point for learners of Vientiane Lao.

The general etymological correspondences between Lao tones and tones in other Tai languages as well as broader East Asia is as follows:

Tone 1 corresponds to B (Qu) and DS2 (Short Yangru).
Tone 2 corresponds to C1 (Yinshang) and DS2 (Long Yinru).
Tone 3 corresponds to C2 (Yangshang) and DL2 (Long Yangru).
Tone 4 corresponds to A2 (Yangping) and DS1 (Short Yinru).
Tone 5 corresponds to A1 (Yinping).