Thai Phonology Summary

When starting to learn Thai, I was dissatisfied with the resources available describing Thai phonology. In particular, I had a hard time finding summarized charts that described the system in a way that makes sense, and I also found the charts representing Thai tone rules very overwhelming, so in this article, I’ve provided some reference charts that I found useful and that other Thai learners may find useful as well.

As I become more familiar with Thai on my learning journey, I may come back to this article and update it with more details and examples.


Here’s the chart for consonants. When learning, note that “Retroflex” and “Breathy” consonants are generally less frequent (despite being used in some commonly used words), so it may make sense to learn those a little later. They were originally used to represent sounds in loan words from languages like Sanskrit and Pali, who had a richer sound inventory than modern Thai. This is why there are now multiple letters representing the same sound in Thai – historically, they were meant for different sounds, but got simplified both by Thai pronouncing the words at the time, as well as through regular sound change as the language evolved.

Note also that I’ve included both old and new style fonts, as they’re different enough in some cases to warrant special attention, and the new font can be a helpful guide for what to pay attention to if the loops and squiggles on the original letters are too distracting.


Thai has a very rich set of vowels, with many vowels, combinations, and distinctive length, and I’ve done my best to summarize everything here.

The green boxes are letters that are trivial to learn because they’re just derived from their long versions by regular processes; for instance, ะ just shortens vowels by acting as a final glottal stop, and ◌็ also serves to shorten vowels. Grey boxes with a ∅ symbol have no written representation in Thai, but surprisingly, those vowels can still exist in the language (just with no way to write them in a distinct way), usually due to interactions with stress as described in [this article].

One more note worth mentioning is that the /a̯/ diphthongs actually do not have phonemic vowel length. To put it another way, they’re always long in live syllables, and always short in dead syllables.1Roengpitya, R., 2002, June. Different durations of diphthongs in Thai: a new finding. In Annual Meeting of the Berkeley Linguistics Society (Vol. 28, No. 2, pp. 43-54).

More about Thai vowels


Rules for deriving Thai tones from syllables can seem very confusing, especially with the giant flowcharts floating around the internet, but they’re actually pretty simple if you just visualize them like below. The “low”, “mid”, and “high” on the left (or on the right, in the case of MAI THO), represent the consonant class of the starting consonant as well as the initial pitch, while words like “LIVE” and “DEAD” represent fixed final pitch targets. By drawing a line between the start and end pitches, you get pretty close representations of how the tonal contours look.

Check out this article on Thai tones for more details on how they’re actually pronounced in modern-day Thai!

More about Thai tone


This article is meant to gather up the knowledge I’ve accrued over the past week of studying Thai. It’s not comprehensive, so I will probably write more articles (and possibly update this one) as I continue to learn the language.

As always, if you have any suggestions or comments on these graphics, I’d love to hear them!

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