Th, Ph, Kh Become T, P, K in Kham Mueang: Tang, Pi, Kam

Th, ph, kh become t, p, k: this Kham Mueang (Northern Thai) sound rule turns up in almost every sentence. Northerners call a path tang (tang, ทาฯงฯ) where Central Thai says thang, an older sister pi (pi, พี่) for phi, and a word kam (kam, คําฯ) for kham. The ท, พ and ค sounds that Central Thai says with a puff of air come out with no puff in Kham Mueang, so they sound like ต, ป and ก.

This article follows R Becomes H and Ch Becomes J and works the same way: where the rule shows in the dictionary, how many entries follow it, what the exceptions are, and whether sister languages share the sound.

What does "no puff of air" mean?

Hold your hand in front of your mouth and say thang, then tang. On the first you feel air hit your hand; on the second you hardly feel any. Linguists call the first kind aspirated and the second unaspirated. Central Thai has both as pairs, ต/ท, ป/พ, ก/ค, but in native Lanna words, where Central Thai has ท, พ or ค the sound usually has no puff.

The Moradok Lanna dictionary says so in its letter entries: ท "is read ta", พ "is read pa, the same base sound as Thai ป", and ค "is read ka". All three are low-class letters, the partners of the high-class ต, ป and ก in Tua Mueang. The classes are explained in High, Mid and Low Consonants in Tua Mueang.

All five Kham Mueang sound rules are together in Kham Mueang Sound Shifts.

More than 1,200 dictionary entries

We counted in the Moradok Lanna dictionary ourselves, comparing the first consonant of each entry's Thai-letter form with the first consonant of its Kham Mueang reading (skipping a leading vowel such as เ แ โ ไ). The count was made on 22 October 2026 over the 17,309 entries that have both fields:

The figures for ค and พ look lower than for ท because many of their words have an ร cluster. Counting only words without an ร or ล cluster, the rule is about equally strong for all three: ท 463 of 470, ค 433 of 444 and พ 360 of 375. Words with an ร cluster nearly all keep the puff (คร 81 of 82, พร 113 of 118).

The figures include compounds (for example ตาง and ตางบน are separate entries), so they are a rough picture, not a linguistic census. Every example below is in the dictionary, with its Thai form and reading exactly as the dictionary gives them.

ท becomes ต

The tung flags used at Lanna merit-making events are filed under the Thai form ทุง, with the meaning "flag". Tai is the name the Tai Yai (Shan) use for themselves, recorded in the same entry; more on the Tai peoples in Meet the Tai.

พ becomes ป

ค becomes ก

The tone mark changes too

In the dictionary's Kham Mueang readings, written in Thai letters, the tone mark often changes along with the consonant: ท่า becomes ต้า and ท้า becomes ต๊า. The reason is Thai spelling: ท พ ค are low-class letters in Thai, while ต ป ก are mid class, so writing the same tone needs a different mark.

Counting only words without an ร or ล cluster and with at most one tone mark in each field: of 170 entries where Central Thai has mai ek, the Kham Mueang reading switches to mai tho in 117; of 179 with mai tho, it switches to mai tri in 120. These figures are only a rough picture. For the six Kham Mueang tones see High, Mid and Low Consonants in Tua Mueang.

When ท พ ค keep their puff

The rule has regular exceptions, several of which the dictionary itself explains:

• An ร cluster. Where Central Thai has คร or พร, Kham Mueang drops the ร but keeps the puff: ครู (teacher) becomes khu (khu, ระฯคู), พริก (chilli) becomes phik (phik, ฯระฯพิกฯ) and พร้า (machete) becomes pha (pha, ระฯพ้า). Under ค the dictionary says a ค read kha is written with the rawong sign in front, and under พ that พ with rawong is read pha. Clusters come in the next article of this series.
• ทร becomes ถ. ทรง is read tha-long (tha-long, ระฯท฿งฯ); under ท the dictionary says ทร is read tha-la and is rare in Lanna.
• Religious and Pali words, such as phra (phra, ระฯพ; the dictionary says Lanna people call a novice pha), khatha (khatha, คาฯถา), "a magic formula", which the dictionary says may also be read ka-tha, and ทอดผ้าป่า, whose reading the dictionary keeps as in Thai.
• ฅ still sounds like ค. Tua Mueang still uses ฅ, as in ฅน, read khon (khon, ฅ฿นฯ), "person". All 251 entries whose Thai form starts with ฅ are read with ค. ธ and ภ, found in Pali words, also keep their puff.
• Pointer pages from Thai words. A few headwords still start with ท because the page tells you what Northerners call the Central Thai thing: ทานทอด, which the dictionary says Northerners call tan tot, and ทับทิม (pomegranate), which they call ba ko kaeng.

English Wikipedia's article on Northern Thai (which we use only as a lead) agrees that ฅ, คร, ฆ, ฒ, พร and ภ stay aspirated in Kham Mueang.

Sister Tai languages: Tai Lue has no puff either

English Wikipedia's article on Northern Thai (a lead) explains that the Central Thai ค ช ท พ that Kham Mueang says without a puff go back to unaspirated voiced sounds in Proto-Tai. In other words, each language changed the same old sounds in its own way: Central Thai made them aspirated, Kham Mueang made them unaspirated.

Tai Lue, a very close relative of Kham Mueang, has the same unaspirated sounds. Wikipedia's article on Tai Lue (a lead) gives these examples:

We have not yet checked this rule for Lao and Isan against a reliable source, so we leave them out here.

A tip for English speakers

English already has both sounds; speakers just don't notice. Wikipedia (a lead) gives the example that the p in pin has a puff of air but the p in spin does not. To say pi, po, tang and kam like a Northerner, say the p, t, k you use after s in spin, stop and sky, then drop the s: that is the no-puff Kham Mueang sound.

Play: th, ph, kh become t, p, k

How many Kham Mueang words from ท, พ and ค do you know? The questions come from 54 real dictionary pairs, and after each answer you see the Lanna script and the dictionary meaning. The "Try it" tab lets you type a Thai word and see which rule applies.

Summary

• Native words that start with ท พ ค in Central Thai are read with the unaspirated ต ป ก in Kham Mueang, as in tang, pi, po, kam, and the written tone mark often changes too.
• In the Moradok Lanna dictionary 1,275 entries follow the rule (ท to ต 463 · ค to ก 443 · พ to ป 369, counted 22 October 2026).
• The main exceptions are words with an ร cluster (ครู becomes khu, พริก becomes phik), religious and Pali words, and ฅ, ธ, ภ, which keep their puff.
• The rule does not always work backwards: most words that start with ต ป ก were ต ป ก already.
• Tai Lue has the same unaspirated sounds, according to Wikipedia's examples.

Read the other rules in Kham Mueang Sound Shifts, R Becomes H and Ch Becomes J, and look up more Kham Mueang words in the Moradok Lanna dictionary.

Sources

• Moradok Lanna dictionary (moradoklanna.com/dict): ตาง · ปี้ · กำ · ตุง · ป้อ, checked and counted 22 October 2026
• Wikipedia. Northern Thai language (a lead on the unaspirated sounds and Proto-Tai)
• Wikipedia. Tai Lue language (a lead; the examples way, father, think)
• Wikipedia. Aspirated consonant (a lead; the pin and spin example)
• Images from Wikimedia Commons, credited under each image