This page brings together basic information about the Tai Tham (Lanna) script and its use for the Northern Thai language. It aims to provide a brief, descriptive summary of the modern, printed orthography and typographic features, and to advise how to write Northern Thai using Unicode.
Sample
Select part of this sample text to show a list of characters, with links to more details.
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Northern Thai is is spoken by the people of Lanna, Thailand, with a smaller community of Lanna speakers in northwestern Laos. Few of the six million speakers of Northern Thai are literate in the Tai Tham script, although there is some rising interest in the script among the young. Since the beginning of the 20th century, the Thai script has been used for the Northern Thai language, although the fact that Thai only has 5 tones to Northern Thai's 6 makes this problematic.
Use of the Lanna traditional script is now largely limited to Buddhist temples, where many old sermon manuscripts are still in active use. There is no active production of literature in the traditional alphabet. The modern pronunciation differs from that prescribed in spelling rules.
ᨲ᩠ᩅᩫᨾᩮᩥᩬᨦ tǔa.mɯ̄aŋNorthern Thai scriptᨣᩤᩴᨾᩮᩬᩨᨦkam˧.mɯːəŋ˧Northern Thai language
In the Thai script this is คำเมือง.
The Lana script is derived from Mon, and before that Pallava.
The Tai Tham script is an abugida, ie. consonants carry an inherent vowel sound that is overridden using vowel signs. In Tai Tham, consonants carry an inherent vowel a. See the table to the right for a brief overview of features for the modern Northern Thai orthography.
Northern Thai text runs left to right in horizontal lines.
Words are not separated by spaces, however syllables may be separated by ZWSP, as long as they don't fall inside a stack.
Each onset consonant is associated with a high, mid, or low class related to tone. Tone is indicated by a combination of the consonant class, the syllable type (checked/unchecked), plus any tone mark.
Tai Tham has stacked consonants, but these do not necessarily indicate consonant clusters. The script is unusual in that any consonant in a stack can retain its inherent vowel, or be associated with a vowel-sign. The sakot, which produces stacks, is never visible.
Stacks can span word boundaries.
Syllable-initial clusters use 2 dedicated code points for the medial l, and a subjoined letter for medial w.
Syllable-final consonant sounds can be written using
6 special diacritics, but otherwise use ordinary letters, which may or may not be subjoined depending on the context.
The Northern Thai orthography has an inherent vowel, and represents vowels using 18 vowel-signs (including 5 prescripts), and 3 consonants. However, unlike Thai and Lao, all vowel-signs are combining marks, and are stored after the base character. Vowels are often written differently when they appear in a closed vs. open syllable.
There is an incomplete set of independent vowels, and standalone vowel sounds are typically written using vowel-signs applied to ᩋ [U+1A4B TAI THAM LETTER A].
This page lists 29 composite vowels (made from 9 vowel-signs, and 3 consonants/diacritics). Composite vowels can involve up to 5 glyphs, eg. ᨠᩮᩬᩨᩋᩡkēɔ̄ɯ̄ʔ̯a which can surround the base consonant(s) on up to 4 sides.
Northern Thai and Khün not only use a slightly different set of characters, but a number of characters have consistently divergeant shapes.
Click on the sounds to reveal locations in this document where they are mentioned.
Phones in a lighter colour are non-native or allophones.
Vowel sounds
Plain vowels
Diphthongs
Consonant sounds
labial
dental
alveolar
post-
alveolar
palatal
velar
glottal
stops
pb
td
k
ʔ
aspirated
pʰ
tʰ
affricates
t͡ɕ
fricatives
f
s
x
h
nasals
m
n
ɲ
ŋ
approximants
w
l
j
The glottal stop is pronounced after short open vowels. An initial glottal stop is also pronounced before independent vowels (see independentvowels).
Syllable-final
labial
dental
alveolar
post-
alveolar
palatal
velar
glottal
stop
p̚
t̚
k̚
ʔ
nasal
m
n
ŋ
approximant
w
j
Vowels
Dashes are used to indicate the location of a consonant or consonant cluster. Prescript vowel-signs have been stored before the hyphen because of the limitations of the font, but in reality all vowel-signs should occur after the consonant they modify.
Vowel sounds mapped to characters
This section maps Northern Thai vowel sounds to common graphemes in the Lanna orthography, where o indicates an open syllable, c a closed syllable, and s a standalone vowel. Click on a grapheme to find other mentions on this page (links appear at the bottom of the page). Click on the character name to see examples and for detailed descriptions of the character(s) shown.
Sounds listed as 'infrequent' are allophones, or sounds used for foreign words, etc.
For some diphthongs ending in -j or -w, Owen indicates that phonetic sequences exist. but offers no examples. Based on other examples, it is assumed here that -j is formed using sakot+ya, and -w using sakot+wa, except where the preceding vowel-sign extends below the baseline (such as for uj).
a following a consonant is not written, but is seen as an inherent part of the consonant letter, so ka is written by simply using the consonant letter ᨠ [U+1A20 TAI THAM LETTER HIGH KA].
Northern Thai uses the following vowel-signs. They may be used on their own, or in combination with others (see composite_vowels).
ᩥ␣ᩦ␣ᩧ␣ᩨ␣ᩩ␣ᩪ␣ᩮ␣ᩫ␣ᩰ␣ᩯ␣ᩬ␣ᩡ␣ᩣ␣ᩤ␣ᩢ␣ ␣ᩱ␣ᩲ␣ᩳ
Characters that produce vowel signs are all combining characters.
In principle, all vowel-signs are typed and stored after the base consonant, whether or not they precede it when displayed. The font takes care of the glyph positioning. However, the Unicode Consortium is currently examining the coding model for Tai Tham. There is a possibility that prescript vowel-signs may be stored before the consonant in future.
Eight vowel-signs are spacing marks, meaning that they consume horizontal space when added to a base consonant.
ᩤ [U+1A64 TAI THAM VOWEL SIGN TALL AA] and ᩣ [U+1A63 TAI THAM VOWEL SIGN AA] are both used to represent the same phoneme. The choice of which is used is a matter of spelling. The taller version is typically used after ᨷ ᩅ ᨴ ᨵ ᨣ and avoids confusion with otherwise similar shapes, eg. ᩅᩣ looks like ᨲ Some textbooks also recommend it's use aftereᨧ ᨻ ᩁ ᨽ
ᩢ [U+1A62 TAI THAM VOWEL SIGN MAI SAT] is commonly used as a vowel, but it also sometimes functions to indicate a final -k sound, eg. ᨯᩬᩢd̯ɔ̄ádɔːkflower
Five vowel-signs appear to the left of the base consonant letter or cluster, eg. ᨯᩱ᩶
These combining marks are in principle stored after the base consonant: the font places the glyph before the base consonant. However, the Unicode Consortium is currently examining the coding model for Tai Tham. There is a possibility that prescript vowel-signs may be stored before the consonant in future. Also, some fonts already require this kind of handling, especially for dealing with complex combinations of characters.
Vowels represented by combinations of the above characters (this list is probably incomplete):
ᩮᩢ␣ᩮᩡ␣ᩰᩡ␣ᩰᩫ␣ᩯᩢ␣ᩯᩡ␣ᩮᩥᩢ␣ᩮᩬᩥᩡ␣ᩮᩥ␣ᩮᩬᩥ␣ᩬᩢ␣ᩰᩬᩡ␣ᩬᩴ␣ ␣᩠ᨿᩮ␣᩠ᨿᩮᩡ␣ᩢ᩠ᨿ␣ᩮᩬᩥᩢ␣ᩮᩬᩨᩢ␣ᩮᩬᩨᩋᩡ␣ᩮᩬᩨᩋ␣ᩮᩬᩨ␣᩠ᩅᩫᩡ␣᩠ᩅᩫ␣᩠ᩅᩢ␣᩠ᩅ᩠ᨿ␣ᩱ᩠ᨿ␣ᩣ᩠ᨿ␣ᩮᩢᩣ␣ᩮᩢᩤShow which combinations contain a given character:
The following list shows where vowel-signs are positioned around a base consonant to produce vowels, and how many instances of that pattern there are. The figure after the + sign represents combinations of Unicode characters, The list includes subjoined WA and YAand the postfixed ᩋ.
Locations where vowel elements can appear, including in complex vowels.
Vowel components can occur concurrently on 4 sides of the base, eg. ᩮᩬᩥᩡ.
Characters that don't appear in the combinations:
ᩦ␣ᩧ␣ᩩ␣ᩪ␣ᩲ␣ᩳ
Standalone vowels
Vowel-signs
For vowels not preceded by a consonant Northern Thai uses ᩋ [U+1A4B TAI THAM LETTER A] with a vowel-sign, eg. ᩋᩧ᩠ᨷ
Independent vowels
Some standalone vowels can be represented using a set of independent vowel letters. The set includes a character to represent the inherent vowel sound, but doesn't cover all such possible vowels.
ᩍ␣ᩎ␣ᩏ␣ᩐ␣ᩑ␣ᩋ
The 5 vowel letters are used in syllable-initial position where there is no consonant onset, eg. ᩑᨠẹkeːk³one
With the high/low categorisation of consonants, Northern Thai writing generally needs only the two combining tone marks below to indicate one of the possible phonetic tones.
᩵␣᩶
Wikipedia lists the following 6 phonemic tones for unchecked syllables in the Changmai dialect of Northern Thai. (It also has sound recordings.)wnl,#Consonants
Tone
Representations
Example
low-rising
˨˦
24
ᩉᩮᩖᩢᩣhel̆áālǎwsharpen
mid-low
˨
22
ᩉᩮᩖᩢ᩵ᩣhel̆á¹ālàwforest
high-falling
glottalised
˥˧
53
ᩉᩮᩖᩢ᩶ᩣhel̆á²āla᷇wliquor
mid-high
˧
33
ᩃᩮᩢᩣḻeáālāwbeautiful
falling
˥˩
51
ᩃᩮᩢ᩵ᩣḻeá¹ālâwtell (story)
high rising-falling
glottalised
˦˥˦
545
ᩃᩮᩢ᩶ᩣḻeá²āláwcoop, pen
This is the list for checked syllables.wnl,#Consonants
Tone
Representations
Example
low-rising
˨˦
24
ᩉᩖᩢᨠhl̆áklǎkpost
high-falling
˥
55
ᩃᩢ᩠ᨠḻá˖kla᷇ksteal
low
˨
22
ᩉᩖᩣ᩠ᨠhl̆ā˖klàːkdiffer from others
falling
˥˩
51
ᩃᩣ᩠ᨠḻā˖klâːkdrag
If there is a vowel over or below a consonant or consonant stack, the tone mark follows the vowel in storage, and is displayed above or alongside the vowel.
Otherwise, the tone is input after the consonant, ie. before a vowel sign that is displayed to the right or below, and appears over the consonant. e
The default fonts used here expect the tone to be typed after a lefted vowel if there is one; after a vowel above, if there is one; before a vowel to the right; and doesn't seem to matter wrt low vowel. See this test. Noto agrees except for lefted vowels.
The following chart shows how to tell which tones are associated with a syllable.
'Checked' means ending in the sound -p, -t, or -k.
Consonant
Checked?
Tone mark
Tone
high
checked
short
2
long
3
open
-
1
᩵
3
᩶
5
mid
checked
short
2
long
3
open
-
2
᩵
3
᩶
5
᩷
2
᩸
1
᩹
6
low
checked
short
6
long
4
open
-
2
᩵
4
᩶
6
Consonants
Consonant to script mapping
This section maps Northern Thai consonant vowel sounds to common graphemes in the Lanna orthography, where h indicates high class, m is mid class, l is low class, and f indicates a final consonant. Click on a grapheme to find other mentions on this page (links appear at the bottom of the page). Click on the character name to see examples and for detailed descriptions of the character(s) shown.
Sounds listed as 'infrequent' are allophones, or sounds used for foreign words, etc.
As part of a diphthong, this is typically rendered using the subjoined form. See consonant_vowels.
Basic consonants
The lists below show consonants in the Northern Thai repertoire. A few consonants have different phonetic realisations in Tai Khün, and ᨢ [U+1A22 TAI THAM LETTER HIGH KXA] is not used by Tai Khün.
Stops
high class
ᨸ␣ᨹ␣ᨲ␣ᨭ␣ᨳ␣ᨮ␣ᨠ
mid class
ᨷ␣ᨯ␣ᩋ
low class
ᨻ␣ᨽ␣ᨴ␣ᨵ␣ᨰ␣ᨣ
Affricates
high class
ᨧ
low class
ᨩ
Fricatives
high class
ᨺ␣ᩈ␣ᩆ␣ᩇ␣ᨨ␣ᨡ␣ᨢ␣ᩉ
low class
ᨼ␣ᨪ␣ᨫ␣ᨥ␣ᨤ␣ᩌ
Nasals
high class
ᩉ᩠ᨾ␣ᩉ᩠ᨶ
low class
ᨾ␣ᨶ␣ᨱ␣ᨬ␣ᨿ␣ᨦ
Other sonorants
high class
ᩀ␣ᩉᩖ
low class
ᩅ␣ᩁ␣ᩃ␣ᩊ
ʨʰ is not a native Northern Thai sound, but rather associated with reading the alphabet out loud and in learned pronunciation of Pali loanwords.o,142
High class nasals & liquids with HA
High and low consonants usually come in pairs, but where they don't the high variant is normally given by subjoining the low consonant below ᩉ [U+1A49 TAI THAM LETTER HIGH HA], eg. ᩉ᩠ᨶᩧ᩵ᨦ
A few consonants have different phonetic realisations in Northern Thai, and ᨢ [U+1A22 TAI THAM LETTER HIGH KXA] is used in Northern Thai but not by Tai Khün.
The letter A
ᩋ [U+1A4B TAI THAM LETTER A] represents a glottal stop. It can be used with vowels at the beginning of a syllable, eg. ᩋᩧ᩠ᨷ It can have very different shapes, as shown by the Northern Thai font ᩋand the Khün font ᩋ
Special consonants
ᩛ␣ᩓ␣ᩔ
The first two of these are special-use consonant diacritics. The second two are ligatures.
Tai Tham is unusual in that subjoined consonants do not only appear where there are consonant clusters. There is a natural tendency to attempt to stack consonants, usually 2 high, whenever possible.
᩠ [U+1A60 TAI THAM SIGN SAKOT] is an invisible character used to produce the subjoined form of a consonant, eg. compareᨠᨠᨠ᩠ᨠ
Sakot doesn't always kill the vowel between two consonants, nor does it create conjuncts, in the sense of merged shapes.
Sakot can follow a vowel-sign. For example, in ᩈᩣ᩠ᨾsā˖m̱saːm¹three the sakot is used to position the final consonant in the syllable below the vowel-sign. This is quite common. A subjoined consonant can also follow a digit, eg. ᪓᩠ᨴ3̣˖ṯsaːm tiːthree times
ᩈᩣ᩠ᨾ
A subjoined consonant positioned below a vowel-sign.
Subjoined consonants are not only syllable-final consonants. The first consonant in a following syllable may also be subjoined, eg. (final r is pronounced as n). eu,654ᨳ᩠ᨶ᩻ᩫᩁtʰ˖ṉʻoṟtʰanonpath
Not all consonants traditionally have subjoined forms, but modern innovations in borrowed terminology suggest that fonts should provide them for all consonants except the old vocalic letters. u,654
This list shows consonants in their normal and subjoined forms. Not all consonants traditionally have subjoined forms, but modern innovations in borrowed terminology suggest that fonts should provide them for all consonants except the old vocalic letters. u,654 You may find that the font applied here doesn't handle all combinations well.
᩻ [U+1A7B TAI THAM SIGN MAI SAM] is used in Northern Thai to identify double-acting consonants, or to indicate that a subjoined consonant begins a new syllable, eg. compare ᨳᩫ᩠ᨶᩁtʰo˖ṉṟtʰonraᨳᩫ᩠ᨶ᩻ᩁtʰo˖ṉʻṟtʰanonpath (final r is pronounced as n).e (It is also used to repeat a word.)
Onset consonants
These combining characters are used to represent the second consonant in syllable-initial clusters.
ᩕ␣ᩖ
In addition, a subjoined w̱ is often found in a syllable-initial cluster, eg. ᨣ᩠ᩅᩣ᩠ᨿḵ˖w̱ā˖ȳkwaːj²buffaloThese initial consonant clusters are limited to kw and xw, although some others are occasionally found and appear to be tending to obsoletion.wnl,#Consonants
Other syllable-initial clusters include the combination of ᩉ [U+1A49 TAI THAM LETTER HIGH HA] plus a subjoined low class consonant to give a high class version, though they are not pronounced as multiple consonants.
Final consonants
Northern Thai text commonly renders syllable-final consonants using regular consonant code points, eg. ᩑᨠẹkeːk³one but sometimes the special combining characters shown below are used.
When regular consonants are used they are commonly subjoined, eg. ᨠᩣ᩠ᩁkā˖rkan¹work but not always. For example, when preceded by a subscript vowel a final consonant may be rendered on the baseline, eg. ᩃᩪᨠḻūkluːk⁴offspringOn the other hand, whereas sometimes in Khün the consonant is subjoined and the subscript vowel is moved to the side of the stack, eg. ᨧ᩠ᨷᩪc˖b̯ūcuːp³kiss in Northern Thai all three may be stacked, ie. ᨧ᩠ᨷᩪ In either case, due to font design or USE (the Universal Shaping Engine) the characters may have to be typed in an order that departs from the spoken order so that they look as expected.
The following diacritics are sometimes used for syllable-final consonants. For more details about usage, click on the characters and follow the links to the character notes.
ᩴ␣ᩙ␣ᩘ␣ᩢ␣ᩝ␣ᩞ
ᩴ [U+1A74 TAI THAM SIGN MAI KANG] may be regarded as a vowel, but it doesn't introduce any vowel sound other than the inherent vowel when used above a consonant on its own.
ᩢ [U+1A62 TAI THAM VOWEL SIGN MAI SAT] is commonly used as a vowel, but it also sometimes functions to indicate a final -k sound, eg. ᨯᩬᩢd̯ɔ̄ádɔːkflower
᩺ [U+1A7A TAI THAM SIGN RA HAAM] is not used for syllable-final consonants in Northern Thai, but rather as a silence marker.
Silent consonants
᩺
᩺ [U+1A7A TAI THAM SIGN RA HAAM] is used in Northern Thai to silence one or more characters in a word. (In Lü it is used as a final n; in Khün it is used as a final r.)
Symbols
Logographs
᪠␣᪡␣᪢
The meaning of each of the logographs is shown above.
Cryptography
᩿
᩿ [U+1A7F TAI THAM COMBINING CRYPTOGRAMMIC DOT] is used singly or multiply beneath letters to give each letter a different value according to some hidden agreement between reader and writer. u,665
Numbers
Digits
᪀␣᪁␣᪂␣᪃␣᪄␣᪅␣᪆␣᪇␣᪈␣᪉᪐␣᪑␣᪒␣᪓␣᪔␣᪕␣᪖␣᪗␣᪘␣᪙
Two sets of digits are in common use: a secular set (Hora) and an ecclesiastical set (Tham). European digits are also found in books. u,665
Text direction
Northern Thai text runs left to right in horizontal lines.
This section brings together information about the following topics:
writing styles;
cursive text;
context-based shaping;
context-based positioning;
baselines, line height, etc.;
font styles;
case & other character transforms.
The orthography has no case distinction, and no special transforms are needed to convert between characters.
Since there are no conjuncts, there is not so much contextual shaping in Tham as in many other Brahmi-descended scripts.
Placement of tone marks often involves special shaping and positioning. See the positions in the examples below.
ᨠᩥ᩶ ᨠᩥ᩵
Positioning of tone marks next to a superscript vowel in the Lanna Alif font.
Font styles
tbd
Text segmentation
Grapheme boundaries
tbd
Word boundaries
Spaces separate phrases. There is no separation of individual words.
A new word may start with a subjoined consonant. Stacking is performed across word boundaries. This means that operations such as line-breaking, word highlighting, etc. have to use an orthographic syllable unit which differs from the underlying phonetic syllables.
ᪧ [U+1AA7 TAI THAM SIGN MAI YAMOK] indicates reduplication of the preceding word, eg. ᨴᩩᨠᪧ ṯukᪧ tuk⁶tuk⁶ every Adverbs, for example, are often derived by reduplicating an adjective.o,149
᩻ [U+1A7B TAI THAM SIGN MAI SAM] is also used in Northern Thai to indicate repetition of a word,e eg. ᨲ᩵ᩣ᩠ᨦ᩻t¹ā˖ŋ̱ʻtaːŋ taːŋdifferent in my view
This section is for any features that are specific to Northern Thai and that relate to the following topics:
general page layout & progression;
grids & tables;
notes, footnotes, etc;
forms & user interaction;
page numbering, running headers, etc.
References
Acknowledgements
Many thanks are due to Richard Wordingham and Patrick Chew for reviewing the initial draft of this material and sending suggestions.
