Thursday, 22 February 2024

The Romanization System of the Thai Language


In June 1967, the Thai government adopted a list of standardized romanized spellings of the names of provinces (changwat) and counties (amphoe) of the whole country according to the recommendation of the Royal Institute.

The system of romanization devised by the Royal Institute in 1954, which is scientific and consistent, has also been applied to the spellings of other names of places, such as streets and lanes, as can be seen on the road signs in Bangkok and other cities.

However, the system is not widely observed by ordinary people, especially in spelling personal names. And nobody seems to have made any effort to popularise it. Consequently, the romanized spellings of names appearing in English newspapers and other English publications in Thailand are very irregular and confusing. For example, the commonest Thai word of greeting Sawatdi is often transliterated as Sawasdee or Sawatdee. Also, Ko (island) is spelled Koh, Ban (house) is spelled Baan and Samlo (tricycle,tuk tuk) is spelled Samlor, though the letter "h" in the word "Koh", the second "a" in "Baan" and the "r" in "Samlor" are superfluous.

Again, people seem to have a special liking for the use of the letter "V" to denote the sound "W" even though there is no "V" sound in the Thai language at all. So, when you see such names as "Visut" and "Vichai" in a newspaper, just pronounce them "Wisut" and "Wichai", and when you see the word "Sukhumvit", the name of an important road in Bangkok, just read "Sukhumwit".

Please note that although in general we observe the official system in romanizing Thai words, and place names in particular, on our website, we do not alter the spellings used by our advertisers.

In order to help standardize the romanized spellings of Thai names, Thaiways has adopted the official system of the Royal Institute with Pattaya and Don Muang as notable exceptions.

But for our website we use popular spellings of some place names and other proper names instead of the official ones. Please also note that there is another system in use for Thai words of Pali origins. See Note No.4 below for the system.

A brief description of the official Romaniation system is given below:

The Thai language has 8 vowel and 14 diphthong phonemes and 19 consonant phonemes represented by the following letters:



  1. All Thai vowels and some diphthongs have their long and short variants, e.g. there is a short "a" and a long "a". This is not indicated in the official romanization system. The difference between long and short vowels and diphthongs is in the length of sound only, and not in its quality.
  2. The consonants "k" "p" and "t" in final positions are unexplosive and unaspirated. They just serve the purpose of stopping the air passage, like the final "m" "n" and "ng" in English words.
  3. The Thai language has fixed tones like many oriental languages. This is not indicated in the romanization system. Foreigners who are interested in learning the correct tones are advised to learn from a native speaker.
  4. The Romanization System for words of Pali origins:

thai vowels

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