Spelling Thai Tones, Simplified

What has the Scottish flag to do with tones in Thai? Read on.

In my extremely leisurely study of Thai, I have reached the point of wanting to learn the rules for expressing the tones in writing. Thai being a tonal language, each Thai syllable takes one of five possible tones. The written language does describe the tones unambiguously, according to arcane and seemingly sadistic rules.

(I indulge my curmudgeonly side here. I well appreciate that an English word like “fraught”—questions like what it means, why it is spelled that way, and what the equivalent present-tense verb is, for example—must be just as frustrating to the foreign-language student.)

In Thai, a given syllable’s tone is affected by several factors (all to be explained later on):

1. The “color” of the consonant—red, black, or blue. (“Color” is my term for these categories, which are generally called high, middle, or low class. Below I explain why the standard names are the worst possible descriptions of these categories.)

2. The type of syllable—“live”, “dead short”, or “dead long”.

3. One of four tone markers:  ,  ,  ,  . Or a syllable may have no marker, which as a mathematician I want to consider as a fifth “zero marker.”

So the total number of combinations amounts to 3×3×5 = 45.  Each of these combinations indicates one of the five tones. The trick is to remember which tone goes with each of the 45 syllable configurations. And at first glance, it’s pretty random. Okay, in practice some of these don’t occur, but there are still a lot of cases to distinguish. See, for example this helpful table from Wikipedia, with a mere 17 cases to memorize. The Wikipedia article uses a table, and a diagram and a flowchart to explain it, and I still think it’s pretty complicated.
After about a day of staring at the table rightway-round, upside-down, and inside-out, I think I’ve managed to pull out the essence. It comes down to just seven short rules, five rules for unmarked syllables and two for marked syllables.

Tones for unmarked syllables

Here are the rules for unmarked syllables:

Lions walk, but….
Red lions rise.
Dogs crawl, but….
Long blue dogs fall.
And short blue dogs fly.

Perhaps some explanation is in order…

First, the five tones themselves. These have descriptive names: mid, low, falling, high, and rising. I won’t be going into much detail on the tones as such; see this Wikipedia diagram for a graphic representation, or this nice video from Benny Lewis. As names go, these are pretty good, each being a rough description of the corresponding tone contour.

But for our purposes, it will be more useful to describe the tones with verbs than with adjectives. Falling and rising are already verbs. The other three tones get new names:

mid=walking
low=crawling
high=flying

I presume these are self-explanatory.

Now to the “colors.” Thai consonants come in three categories, the main function of which appears to be giving clues as to tones. For example, we could think of ข and ค as two different versions of “K”, which impart different tones (not always the same) to the syllables they head. For example, ขา is pronounced something like “kah” with a mid tone and คา is pronounced exactly the same, except with a rising tone. Again, the “color” of the consonant is merely one of several factors determining the tone of the syllable.
Traditionally these three categories are called “high”, “mid”, and “low.” (Note that in the Wikipedia table, these are the headings of the three columns.) As mentioned before, these are in fact the worst possible names for the three categories. First of all, as “high”, “mid” and “low” are already used as names for three of the five tones, describing consonants by the same terms is a recipe for confusion. The exception would be if, for example, a “high” consonant always gave a syllable the “high” tone for example, but such is not the case. Check the “high” column of the table again. Note that the “high” tone is the only one which cannot occur with a “high” consonant. Similarly for “low” tones and “low” consonants.
So I’m dropping the “high”, “mid”, “low” terminology and using colors instead. Previously I used vowel sounds to help remember the consonant class. So-called “high” class consonants are given names with vowels E and I, so from now on I call these “rEd” consonants. So-called “low” class consonants are given names with vowels O and U, so from now on I call these “blUe” consonants. And so-called “mid” class consonants are given names with the vowels A, so from now on I call these “blAck” consonants. (It just happens that the “red” consonant column of the Wikipedia table is shaded red, and the “blue” column is shaded blue. Huh, fate.) For the record:

The blue consonants are: งณนมญยรลฬวคฅฆชฌฑฒทธพภฟซฮ
The red consonants are: ขฃฉฐถผฝศษส
The black consonants are:กจดฎฏตบปอ

And finally, the tone is affected by syllable type. “Live” syllables are distinguished from “dead.” The former end in a vowel or a “sonorant” (like M, N, etc.). The latter end in a “plosive” (like “K”. “T”, etc.). In short, if you can imaging singing the syllable, stretching it out indefinitely (like “Caaaaaaaannnnnnnn…”) then it’s a live syllable. If not (like “Caaaaaaat”—once you hit the “t” you are done) then it’s a dead syllable.
Among live syllables, it also makes a difference whether the vowel of the syllable is long or short.
For our purposes it will be more useful to describe syllable types with nouns. So live syllables are “lions” and dead syllables are “dogs.” (Live like a lion, or die like a dog.)
This is all the background needed for our five rules. To summarize:
Colors represent consonant classes.
Verbs (of motion) represent tones.
Animals represent syllable types.
Now let’s revisit our five rules for unmarked syllables.

Lions walk, but…. In other words, a live syllable gets a mid tone, with the exception that…

Red lions rise. A live syllable with a high-class consonant gets a rising tone.

Dogs crawl, but.… A dead syllable gets a low tone, with the exception that…

Long blue dogs fall. A long dead syllable with a low-class consonant gets a falling tone.

And short blue dogs fly. A short dead syllable with a low-class consonant gets a high tone.

That’s it. These five rules encompass all the information in the top three rows of the Wikipedia table. It can’t really get better than this, because you need at least one rule for each tone.

Tones for marked syllables.

Who invented the Thai script? It would have been so easy just to let a syllable’s tone be specified by the tone mark. And we could dispense with almost half the Thai alphabet. Oh, well….

We give each of the tone marks a name based on the tone it describes in most cases:

        crawl
        fall
        fly
        rise

We then just need rules to handle the exceptions. Looking at the bottom four rows of the Wikipedia table, we see that syllable type (lion versus dog) is irrelevant. We also see that red and black syllables are always the same, except for the blank areas (which represent situations that never occur—so we need not worry about them). The only exceptions concern blue syllables. We use “bluejay” to represent such a syllable—dead or alive, but starting with a blue consonant.
Just two rules for two exceptions:
Crawling bluejays fall. (In other words, a syllable with a blue consonant and marked with ่ (crawl) gets a falling tone.
Falling bluejays fly. (In other words, a syllable with a blue consonant and marked with   (fall) gets a rising tone.

Did I say seven rules?

It turns out there are two loopholes described in the comments following the Wikipedia table. Both concern a consonant changing its color under certain conditions.
In the first case any of the consonants งญนมวยรล, which are normally blue, change to red when they follow an unadorned red or black consonant or a silent letter ห (H). These particular blue consonants have no red equivalents (for example, ญ and น are both blue “N”, but the Thai alphabet has no red “N”), so you can think of this as a way of improvising a red consonant.
In the second case, the letter ย, which is normally blue, changes to black when it is prefixed by อ. This rule is limited to four words which start with the sequence อย: อยาก, อย่า, อย่าง, and อยู่. It turns out all four words come out with low tones, the first because “(Black) dogs crawl”; the other three because they carry the “crawling” marker.

See also:

Learn the Thai Alphabet in One Hour  

...And Learn the Thai Vowels