History

Replica of the Ramkhamhaeng inscription, the oldest inscription using Thai script

The Thai alphabet is probably derived from the Old Khmer script (อักขระเขมร), which is a southern Brahmic script of the Indic family. According to tradition it was created in 1283 by King Ramkhamhaeng the Great (พ่อขุนรามคำแหงมหาราช).

Alphabet listing

You will need a Unicode-capable browser and font that contains the Thai alphabet to view the Thai letters below.

Consonants

There are 44 consonants representing 21 distinct consonant sounds. Duplicate consonants represent different Sanskrit and Pali consonants pronounced identically in Thai. Their continued use is necessary to differentiate among unrelated loan-words which are Thai homophones. The consonants are divided into three classes - low, middle and high - which determine the tone of the following vowel. There are in addition four consonant-vowel combination characters not included in the tally of 44.

To aid learning, each consonant is traditionally associated with a Thai word that either starts with the same sound, or features it prominently. For example, the name of the letter ข is kho khai (ข ไข่), in which kho is the sound it represents, and khai (ไข่) is a word which starts with the same sound and means "egg".

Two of the consonants (kho khuat and kho khon) aren't used in written Thai anymore. Some say that when the first Thai typewriter was developed by Edwin Hunter McFarland in 1892, there was simply no space for all characters, thus two had to be left out.

Equivalents for Romanization are shown in the table below. Many consonants are pronounced differently at the beginning and at the end of a syllable. The entries in columns initial and final indicate the pronunciation for that consonant in the corresponding positions in a syllable. Where the entry is "-", the consonant may not be used to close a syllable. Where a combination of consonants ends a written syllable, only the first is pronounced; possible closing consonant sounds are limited to 'k', 'm', 'n', 'ng', 'p' and 't'.

Although an official standard for Romanisation is defined by the Royal Thai Institute, many publications use different Romanisation systems. In daily practice, a bewildering variety of Romanisations are used, making it difficult to know how to pronounce a word, or to judge if two words (e.g. on a map and a street sign) are actually the same. For more precise information, an equivalent from the International Phonetic Alphabet (IPA) is given as well.

Each consonant is assigned to a "class" (Low, Middle, High), which plays a role in determining the tone with which the syllable is pronounced.

• Consonant-vowel combination characters, not members of any group.

• • อ is a special case in that at the beginning of a word it is used as a silent initial for syllables that start with a vowel (all vowels are written relative to a consonant — see below).

Vowels

Thai vowel sounds and diphthongs are written using a mixture of vowel symbols, consonants, and combinations of vowel symbols. Each vowel is shown in its correct position relative to an initial consonant (indicated by a dash "–") and sometimes a final consonant as well (second dash). Note that vowels can go above, below, left of or right of the consonant, or combinations of these places. If a vowel has parts before and after the initial consonant, and the syllable starts with a consonant cluster, the split will go around the whole cluster.

The pronunciation is indicated by the International Phonetic Alphabet and the Romanisation according to the Royal Thai Institute as well as several variant Romanisations often encountered. A very approximate equivalent in Northeastern US English is given.

• vowels or diphthongs written with consonant symbols

Diacritics

Each mark is shown in its correct location relative to the consonant kor kai. The names of the tones are derived from the numbers one, two, three and four in an Indic language.

Other symbols

Thai in computing

TIS-620 is the best-established character set and character encoding for the Thai alphabet. TIS-620 has been adopted verbatim in the Unicode range for Thai, U+0E00 ... U+0E7F.