Learn To Speak Thai: The Three Thai Consonant Classes

As if learning a whole new alphabet with a total of 44 consonants wasn’t enough, the Thai language then also splits them into 3 different consonant classes. Not unlike short and long vowels, the Thai consonant classes are necessary to cover if you want to learn to speak Thai properly. They play into the whole challenge that is the Thai tone rules which dictate the tone you should use when speaking. So what are these three classes and what impact do they have on pronunciation? That is what we will be discussing today.

What Are The Three Thai Consonant Classes

While there are 44 Thai consonants in total when counting individual letters, they all together only make 21 unique sounds. This makes sense as I can’t even think of 44 different and unique sounds myself. Anyway, each of the 21 Thai consonant sounds can be split into one of three classes: low, mid, and high. 

Just to make sure it is clear, these are not related to the Thai tones and act differently. However, the classes do ultimately reveal which tone to use when in a word, but the classes do not directly translate into the tone with the same name. Does that make sense?

Essentially, there are some qualities of how the consonants sound or are pronounced that will allow you to organize them into the different classes. That means there are groups within groups. Thankfully, they more or less line up into specific classes.

As mentioned, these classes will then tell you the tone you should use when you come across words that contain certain tone marks. Let’s take a quick look at the tone marks now.

Thai Tone Marks

We have discussed before how to work out the tone when there is no tone mark based on live and dead syllables. The Thai language is tonal and makes use of four different tone marks. Two of these tone marks correlate directly to a particular tone, while the other two change depending on the initial consonant of the syllable.

Tone Mark Thai Transliteration Corresponding Tone (Initial Consonant)
Low Mid High
-่ ไม้เอก mai ehk Falling Low Low
-้ ไม้โท mai tho High Falling Falling
-๊ ไม้ตรี mai tri High
-๋ ไม้จัตวา mai chatawa Rising

As you can see in the chart, the class of the initial consonant in a syllable affects the tone used. Well, at least for the first two. Now we have that out of the way, let’s take a look which consonants belong to which class.

Which Consonants Belong To Which Class?

As a quick reference, I thought I would put together a table to show you which consonants belong to which class:

Class Consonant

If you were hoping for a bit more of an intuitive way to learn them, then you are in luck, there is a way to work out which class they belong to based on the sound they make.

High-Class Consonants

One group of Thai consonants are the Aspirate-Fricatives (both words that describe the way your mouth produces the sound such as with a burst of air or by forcing air through a tight space like the lower lip). There are seven sounds in this group, made up of eleven letters.

Here is where things get a bit confusing. While all high-class consonants are aspirates, not all aspirates are high class. Some actually belong to the low class. Here is a breakdown of which belong to which class:

Class Aspirate-Fricatives
kh ch s th ph f h

Low-Class Consonants

The low-class consonant group is the largest by far. As well as the majority of the Aspirate-Fricatives, sonorants are also part of this group. We have talked about sonorants before when looking at the different Thai syllables. Sonorants are sounds/syllables that you hold the sound for longer. There are fourteen sounds in this group, made up of twenty-four letters:



kh ch s th ph f h


ng n m y r l w

All of these sonorant consonants belong to the low class. There are ten in total, though one of these is not widely used. Try to remember the sounds they make and connect sonorants with the low-class consonants in your mind.

Mid-Class Consonants

Finally, we have the mid-class consonants. Basically, any consonants that don’t belong to the low or high classes are placed here. Specifically, these are the unaspirated sounds. There are nine characters making seven sounds in total in this group:



g j d dt b bp

Think of these as sounds that you do not hold or use a puff of air. If you come across a letter like that, then you will likely be facing a mid-class consonant.

Getting Through The Grammar

This is another one of those topics that often get overlooked but are essential when you want to move from a beginner to an experienced Thai speaker. Learning to speak Thai may not be the easiest (when is it ever easy?) but it not as difficult as it first appears. Once you nail learning the different Thai consonant classes, you will be well on your way to pronouncing words with their proper tone, making you much easier to understand. Keep up the good work?

If you are looking to improve your Thai speaking abilities further, the Ling Thai app is your best bet. It offers games, tests, and more to help you learn and reinforce what you already know. Try it for free today.

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