Consonants

There are 44 consonant characters in Thai representing 20 consonant sounds. The 44 consonants are grouped into 3 classes: HIGH, MID and LOW, classified by their tonal quality, i.e. their inherent tones and their tonal interaction with the tone marks. HIGH consonants are shown in red, MID consonants are shown in black, and LOW consonants are shown in blue.

Of these 44 consonants, 2 are obsolete: and .

The following listing (reading across and then down) follows Thai alphabetical order.

Vowels

There are 9 short monopthong (single) vowel sounds and 9 long counterpart vowel sounds plus 3 diphthongs sounds in Thai. However, there are 28 so called vowel forms. The Thai vowel forms do not all follow initial consonants, some are placed before the initial consonants, some after the consonants, some above the consonants, and some underneath the consonants. The vowels that are "complex" forms (i.e. composed of more than one part) can be placed around the consonants. The following table shows all the vowel forms in Thai and their location in relation to the initial consonants. The letter is used as an initial consonant place holder in this table.

Tone Marks

There are 5 tones in Standard Thai: mid, low, falling, high and rising.

The following is a chart of average fundamental frequency contours for tones adapted from the chart given in Jackson Gandour (1976).

There are 4 tone marks in Thai. They are placed above the initial consonant of the syllable whose tone they mark, or on top of the vowel (if the vowel is placed above the consonant). The 4 tone markers are:

The Tone markers and , which have limited distribution, are thought to have been developed later in order to write borrowed words from other dialects or languages.

The tonal value of the tone marks depends on the class of the initial consonant and the type of syllable (open or closed syllable) that they mark. The following table gives the form and tonal value of the tone marks, when used with initial consonant of each consonants class in live syllable: