Tai migration

The ancestors of the Northern Thai people were speakers of Southwestern Tai dialects that migrated from what is now southeastern China, specifically what is now Guangxi and northern Vietnam where the diversity of various Tai languages suggests an Urheimat. The Southwestern Tai languages began to diverge from the Northern and Central branches of the Tai languages, covered mainly by various Zhuang languages, sometime around 112 AD, but likely completed by the sixth century.^[3] Due to the influx of Han Chinese soldiers and settlers, the end of the Chinese occupation of Vietnam, the fall of Jiaozhi and turbulence associated with the decline and fall of the Tang dynasty led some of the Tai peoples speaking Southwestern Tai to flee into Southeast Asia, with the small-scale migration mainly taking place between the eighth and twelfth centuries. The Tais split and followed the major river courses, with the ancestral Northern Thai originating in the Tai migrants that followed the Mekong River.^[4]

Indianized kingdoms

Ancestors of the Northern Thai people established Ngoenyang, an early kingdom that existed between the 7th to 13th centuries, as well as smaller kingdoms like Phayao, in what is now modern-day northern Thailand. They settled in areas adjacent to the kingdom of Hariphunchai, coming into contact with Mon-speaking people whose writing system was eventually adapted for the Northern Thai language as the Tai Tham script.^[5] In the 13th century, King Mangrai consolidated control of these territories, establishing the kingdom of Lan Na. In the 15th century, King Tilokkarat ushered in a golden age for Northern Thai literature, with a profusion of palm leaf manuscripts written in Tai Tham, using vernacular Northern Thai and interspersed with Pali and Buddhist Indic vocabulary.^[6][5]

Thai subordination

In 1775, Kawila of Lampang revolted with Siamese assistance, and captured the city, ending 200 years of Burmese rule. Kawila was installed as the prince of Lampang and Phraya Chaban as the prince of Chiang Mai, both as vassals of Siam. In 1899, Siam annexed the Northern Thai principalities, effectively dissolving their status as sovereign tributary states.

The Compulsory Education Act of 1921 banned schools and temples from using languages other than Central Thai (standard Thai), in an effort to bring remote regions under Siamese control.^[5] Northern Thai was relegated from the public sphere, with influential religious leaders like Khruba Srivichai jailed for using Northern Thai in sermons.^[5] In the 1940s, authorities promulgated Thai cultural mandates that reinforced the importance of learning and using Central Thai as the prestige language.^[5]

These economic and educational pressures have increased the use of standard Thai to the detriment of other regional languages like Northern Thai.^[7][8] Today, Northern Thai is typically code-switched with standard Thai, especially in more developed and urbanized areas of Northern Thailand, whereas exclusive use of Northern Thai remains prevalent in more remote areas.^[8]

Consonants

Vowels

The basic vowels of the Northern Thai language are similar to those of Standard Thai. They, from front to back and close to open, are given in the following table. The top entry in every cell is the symbol from the International Phonetic Alphabet, the second entry gives the spelling in the Thai alphabet, where a dash (–) indicates the position of the initial consonant after which the vowel is pronounced. A second dash indicates that a final consonant must follow.

The vowels each exist in long-short pairs: these are distinct phonemes forming unrelated words in Northern Thai,^[14] but usually transliterated the same: เขา (khao) means "they/them", while ขาว (khao) means "white".

The long-short pairs are as follows:

The basic vowels can be combined into diphthongs. For purposes of determining tone, those marked with an asterisk are sometimes classified as long:

Additionally, there are three triphthongs, For purposes of determining tone, those marked with an asterisk are sometimes classified as long:

Tones

There are six phonemic tones in the Chiang Mai dialect of Northern Thai: low-rising, low-falling, high-level with glottal closure, mid-level, high-falling, and high-rising.^[16] or low-rising, mid-low, high-falling, mid-high, falling, and high rising-falling^[17]

Adjectives and adverbs

There is no morphological distinction between adverbs and adjectives. Many words can be used in either function. They succeed the word which they modify, which may be a noun, verb, or another adjective or adverb.

• ᨾᩯ᩵ᨿᩥ᩠ᨦᨳᩮᩢ᩶ᩣ / แม่ญิงเฒ่า (mae nying thao, [mɛ̂ː.ɲīŋ.tʰa᷇w]) an old woman
• ᨾᩯ᩵ᨿᩥ᩠ᨦᨴᩦ᩵ᨳᩮᩢ᩶ᩣᩅᩮᩥ᩠ᨿ / แม่ญิงตี้เฒ่าโวย (mae nying ti thao woi, [mɛ̂ː.ɲīŋ.tîː.tʰa᷇w.wōːj]) a woman who became old quickly

Because adjectives can be used as complete predicates, many words used to indicate tense in verbs (see Verbs:Aspect below) may be used to describe adjectives.

• ᨡ᩶ᩣᩉᩥ᩠ᩅ / ข้าหิว (kha hiw, [kʰa᷇ː hǐw]) I am hungry.
• ᨡ᩶ᩣᨧᩢᩉᩥ᩠ᩅ / ข้าจะหิว (kha cha hiw, [kʰa᷇ː t͡ɕa.hǐw]) I will be hungry.
• ᨡ᩶ᩣᨠ᩵ᩣᩴᩃᩢ᩠ᨦᩉᩥ᩠ᩅ / ข้ากะลังหิว (kha kalang hiw, [kʰa᷇ː ka.lāŋ hǐw]) I am hungry right now.
• ᨡ᩶ᩣᩉᩥ᩠ᩅᩓ᩠ᩅ / ข้าหิวแล้ว (kha hiu laew, [kʰa᷇ː hǐw lɛ́ːw]) I am already hungry.

Verbs

Verbs do not inflect. They do not change with person, tense, voice, mood, or number; nor are there any participles.

• ᨡ᩶ᩣᨲᩦᨻᩮᩥ᩠᩵ᨶ / ข้าตี๋เปิ้น (kha ti poen, [kʰa᷇ː tǐː pɤ̂n]), I hit him.
• ᨻᩮᩥ᩠᩵ᨶᨲᩦᨡ᩶ᩣ / เปิ้นตี๋ข้า (poen ti kha, [pɤ̂n tǐː kʰa᷇ː]), He hit me.

The passive voice is indicated by the insertion of ᨯᩰ᩠ᨶ / โดน (don, [dōːn]) before the verb. For example:

• ᨻᩮᩥ᩠᩵ᨶᨯᩰᩫ᩠ᨶᨲᩦ / เปิ้นโดนตี๋ (poen don ti, [pɤ̂n dōːn tǐː]), He is hit or He got hit. This describes an action that is out of the receiver's control and, thus, conveys suffering.

To convey the opposite sense, a sense of having an opportunity arrive, ᨯᩱ᩶ / ได้ (dai, [da᷇j], can) is used. For example:

• ᨻᩮᩥ᩠᩵ᨶᨧᩢᨯᩱ᩶ᨸᩱᩋᩯ᩠᩵ᩅᨾᩮᩬᩥᨦᩃᩣ᩠ᩅ / เปิ้นจะได้ไปแอ่วเมืองลาว (poen cha dai pai aew mueang lao, [pɤ̂n t͡ɕa.da᷇j pǎj ʔɛ̀w mɯ̄a̯ŋ lāːw]), He gets to visit Laos.
• ᨻᩮᩥ᩠᩵ᨶᨲᩦᨯᩱ᩶ / เปิ้นตี๋ได้ (poen ti dai, [pɤ̂n tǐː da᷇j]), He is/was allowed to hit or He is/was able to hit

Negation is indicated by placing บ่ (bor,[bɔ̀ː] or [bàʔ] not) before the verb.

• ᨻᩮᩥ᩠᩵ᨶᨷᩴ᩵ᨲᩦ / เปิ้นบ่ตี๋, (poen bor ti, [pɤ̂n bɔ̀ː tǐː]) He is not hitting. or He not hit.

Aspect is conveyed by aspect markers before or after the verb.

Present can be indicated by ᨠ᩵ᩣᩴᩃᩢ᩠ᨦ / กะลัง (kalang, [ka.lāŋ], currently) or ᨠ᩵ᩣᩴᩃᩢ᩠ᨦᩉᩡ / กะลังหะ (kalangha, [ka.lāŋ.hà], currently) before the verb for ongoing action (like English -ing form), by ᩀᩪ᩵ / อยู่ (yu, [jùː]) after the verb, or by both. For example:

• ᨻᩮᩥ᩠᩵ᨶᨠ᩵ᩣᩴᩃᩢ᩠ᨦᩉᩡᩃᩫ᩠᩵ᨶ / เปิ้นกะลังหะล่น (poen kalangha lon, [pɤ̂n ka.lāŋ.hà lôn]), or
• ᨻᩮᩥ᩠᩵ᨶᩃᩫ᩠᩵ᨶᩀᩪ᩵ / เปิ้นล่นอยู่ (poen lon yu, [pɤ̂n lôn jùː]), or
• ᨻᩮᩥ᩠᩵ᨶᨠ᩵ᩣᩴᩃᩢ᩠ᨦᩃᩫ᩠᩵ᨶᩀᩪ᩵ / เปิ้นกะลังหะล่นอยู่ (poen kalanɡha lon yu, [pɤ̂n ka.lāŋ.hà lôn jùː]), He is running.

Future can be indicated by ᨧᩢ / จะ (cha, [t͡ɕǎʔ], will) before the verb or by a time expression indicating the future. For example:

• ᨻᩮᩥ᩠᩵ᨶᨧᩢᩃᩫ᩠᩵ᨶ / เปิ้นจะล่น (poen cha lon, [pɤ̂n t͡ɕa.lôn]), He will run or He is going to run.

Past can be indicated by ᨯᩱ᩶ / ได้ (dai, [da᷇j]) before the verb or by a time expression indicating the past. However, ᩓ᩠ᩅ / แล้ว (laew,  :[lɛ́ːw], already) is often used to indicate the past aspect by being placed behind the verb. Or, both ได้ and แล้ว are put together to form the past aspect expression. For example:

• ᨻᩮᩥ᩠᩵ᨶᨯᩱ᩶ᨠᩥ᩠ᨶ / เปิ้นได้กิ๋น (poen dai kin, [pɤ̂n da᷇j kǐn]), He ate.
• ᨻᩮᩥ᩠᩵ᨶᨠᩥ᩠ᨶᩓ᩠ᩅ / เปิ้นกิ๋นแล้ว (poen kin laew, [pɤ̂n kǐn lɛ́ːw], He has eaten.
• ᨻᩮᩥ᩠᩵ᨶᨯᩱ᩶ᨠᩥ᩠ᨶᩓ᩠ᩅ / เปิ้นได้กิ๋นแล้ว (poen dai kin laew, [pɤ̂n da᷇j kǐn lɛ́ːw]), He's already eaten.

Aspect markers are not required.

• ᨡ᩶ᩣᨠᩥ᩠ᨶᨴᩦ᩵ᩉᩢ᩠᩶ᨶ / ข้ากิ๋นตี้หั้น (kha kin tihan, [kʰa᷇ kǐn tîː.ha᷇n]), I eat there.
• ᨡ᩶ᩣᨠᩥ᩠ᨶᨴᩦ᩵ᩉᩢ᩠᩶ᨶᨲᩅᩤ / ข้ากิ๋นตี้หั้นตะวา (kha kin tihan tawa, [kʰa᷇ kǐn tîː.ha᷇n ta.wāː]), I ate there yesterday.
• ᨡ᩶ᩣᨠᩥ᩠ᨶᨴᩦ᩵ᩉᩢ᩠᩶ᨶᩅᩢ᩠ᨶᨻᩕᩪᨠ / ข้ากิ๋นตี้หั้นวันพูก (kha kin tihan wanphuk, [kʰa᷇ kǐn tîː.ha᷇n wān.pʰûːk]), I'll eat there tomorrow.

Words that indicate obligation include at cha (ᩣ᩠ᨧᨧᩢ / อาจจะ), na cha (ᩉ᩠ᨶ᩶ᩣᨧᩢ / น่าจะ), khuan cha (ᨤ᩠ᩅᩁᨧᩢ / ควรจะ)^{[dubious – discuss]}, and tong (ᨲ᩶ᩬᨦ / ต้อง).

• at cha (ᩋᩣ᩠ᨧᨧᩢ / อาจจะ, [ʔàːt.t͡ɕǎ]) Might

• ᨻᩮᩥ᩠᩵ᨶᩋᩣ᩠ᨧᨧᩢᨾᩣ / เปิ้นอาจจะมา (poen at cha ma, /pɤ̂n ʔàːt t͡ɕa.māː/) He might come.

• na cha (ᩉ᩠ᨶ᩶ᩣᨧᩢ / น่าจะ, [na᷇ː.t͡ɕǎ]) Likely to

• ᨻᩮᩥ᩠᩵ᨶᩉ᩠ᨶ᩶ᩣᨧᩢᨾᩣ / เปิ้นน่าจะมา (poen na cha ma, /pɤ̂n na᷇ː.t͡ɕa.māː/) He is likely to come.

• khuan cha (ᨤ᩠ᩅᩁᨧᩢ / ควรจะ, [kʰūan.t͡ɕǎ]) Should

• ᨻᩮᩥ᩠᩵ᨶᨤ᩠ᩅᩁᨧᩢᨾᩣ / เปิ้นควรจะมา (poen khuan cha ma, /pɤ̂n kʰūan.t͡ɕa.māː/) He should come.

• tong (ᨲᩬ᩶ᨦ / ต้อง, /tɔ᷇ːŋ/) Must

• ᨻᩮᩥ᩠᩵ᨶᨲᩬ᩶ᨦᨾᩣ / เปิ้นต้องมา (poen tong ma, /pɤ̂n tɔ᷇ŋ māː/) He must come.

Actions that wherein one is busily engaged can be indicated by มัวก่า (mua ka, [mūa̯.kàː]).

• ᨣᩴ᩵ᨾ᩠ᩅᩫᨣ᩵ᩤᨠᩥ᩠ᨶᩉᩢ᩠᩶ᨶᨶᩰᩬᩡ / ก่อมัวก่ากิ๋นหั้นเนาะ (kor mua ka kin han nor, [kɔ̀ mūa̯ kàː kǐn ha᷇n nɔ᷇ʔ]) (It's that you/he/she) just keeps on eating it like that, you know?

Words that express one's desire to do something can by indicated by khai (ใค่) and kan (กั๊น).

• khai (ᨣᩕᩲ᩵ / ใค่, /kʰâj/, to want, to desire)

• ᨡ᩶ᩣᨧᩮᩢ᩶ᩣᨣᩕᩲ᩵ᨠᩥ᩠ᨶ / ข้าเจ้าใค่กิ๋น (kha.chao khai kin, [kʰa᷇ː.t͡ɕa᷇w kʰâj kǐn]) I want to eat.

• kan (ᨣᩢ᩠᩶ᨶ / กั๊น, /kán/, to try)

• ᨡ᩶ᩣᨧᩮᩢ᩶ᩣᨣᩢ᩠᩶ᨶᨠᩥ᩠ᨶ / ข้าเจ้ากั๊นกิ๋น (kha.chao kan kin, [kʰa᷇ː.t͡ɕa᷇w kán kǐn]) I try to eat.

Phor tha wa (ᨹᩬᩴ᩵ᨵ᩵ᩤᩅ᩵ / ผ่อท่าว่า, [pʰɔ̀ː.tʰâː.wâː]) is used to give the impression or sensation of being something or having a particular quality.

• ᨹᩬᩴ᩵ᨵ᩵ᩤᩅ᩵ᩤᨻᩮᩥ᩠᩵ᨶᨻᩖᩥᨠᨾᩣᩓ᩠ᩅ / ผ่อท่าว่าเปิ้นปิ๊กมาแล้ว (phor tha wa poen pik ma laew, [pʰɔ̀ː tʰâː wâː pɤ̂n pi᷇k māː lɛ́ːw]) It seems that he has returned.

Final particles

Northern Thai has a number of final particles, which have different functions.

Nouns

Nouns are uninflected and have no gender; there are no articles.

Nouns are neither singular nor plural. Some specific nouns are reduplicated to form collectives: ᩃᩡᩋᩬ᩵ᩁ / ละอ่อน (la-orn, [la.ʔɔ̀ːn], child) is often repeated as ᩃᩡᩋᩬ᩵ᩁᪧ ละอ่อน ๆ (la-orn la-orn, [la.ʔɔ̀ːn la.ʔɔ̀ːn],) to refer to a group of children.

The word ᩉ᩠ᨾᩪ᩵ / หมู่(mu, [mùː]) may be used as a prefix of a noun or pronoun as a collective to pluralize or emphasise the following word. (ᩉ᩠ᨾᩪ᩵ᨹᩫ᩠ᨾ / หมู่ผม, mu phom, [mùː pʰǒm], we (exclusive), masculine; ᩉ᩠ᨾᩪ᩵ᩁᩮᩢᩣ / หมู่เฮา mu hao, [mùː hāw], emphasised we; ᩉ᩠ᨾᩪ᩵ᩉ᩠ᨾᩣ / หมู่หมา mu ma, [mùː mǎː], (the) dogs).

Plurals are expressed by adding classifiers, used as measure words (ลักษณนาม), in the form of noun-number-classifier ( ᨣᩕᩪᩉ᩶ᩣᨤᩫ᩠ᨶ / คูห้าคน, "teacher five person" for "five teachers").

Pronouns

Pronouns may be omitted once they have already been established in the first sentence, unless the pronoun in the following sentences is different from the first sentence. The pronoun "you" may also be omitted if the speaker is speaking directly to a second person. Moreover, names may replace pronouns, and they can even replace the first person singular pronoun.

Different sounds

Unlike Northern Thai, Standard Thai lacks alveolo-palatal nasal sound (/ɲ/). Thus, the alveolo-palatal nasal sound (/ɲ/) and the palatal approximant sound (/j/) in Northern Thai both correspond to the palatal approximant sound in Standard Thai:

Unlike Northern Thai, Standard Thai lacks a high-falling tone ([˥˧]). The high falling tone ([˥˧]) and falling tone ([˥˩]) in Northern Thai both correspond to the falling tone in Standard Thai ([˥˩]).

Different words

Many words differ from Standard Thai greatly:

Similar words

There is not a straightforward correspondence between the tones of Northern and Standard Thai. It also depends on the initial consonant, as can be seen from the merged Gedney tone boxes for Standard Thai and the accent of Chiang Mai:

Note that the commonalities between columns are features of the Chiang Mai accent. On the other hand, the relationships between rows are typical of Northern Thai, being found for at least for Chiang Mai, Chiang Rai,^[20] Phayao,^[20] Nan and Prae,^[20] and extending at least to Tak^[20] and the old 6-tone accent of Tai Khuen,^[20] except that the checked syllables of Chiang Rai are more complicated.

The primary function of a tone box is etymological. However, it also serves as a summary of the rules for tone indication when the writing system is essentially etymological in that regard, as is the case with the major Tai-language writing systems using the Thai, Lanna, New Tai Lue, Lao and Tai Dam scripts.

Some words differ only as a result of the regular tone correspondences:

Other tone differences are unpredictable, such as:

Some words differ in a single sound and associated tone. In many words, the initial ร (/r/) in Standard Thai corresponds to ฮ (/h/) in Northern Thai: