How to read in Thai
Reading from zero: a syllable assembles around its consonant, and the tone is computed, not written. The script names itself “อักษรไทย”. The alphabet has 63 letters. The writing course covers them all, plus 4 signs that do not count as letters: อ่, อ้, อ๊ and อ๋. The characters come a few per session — in two or three weeks a shop sign stops being a picture.
How the line works
Thai runs left to right like the Latin script but is built differently in three ways. First: there are no spaces between words — a space marks a pause between phrases, and the words themselves run together. Second: there are no capital letters, so nothing in the line's shape tells a sentence from a word. Third: vowels are written around the consonant — before it, above it, below it, and one of them even wraps around it.
A Thai syllable is: consonant + vowel (+ a final consonant). A vowel that starts a syllable needs a seat — the consonant อ. On its own it is a tiny catch in the throat, like the break in "uh-oh". Its usual job is to carry the vowel: in อา the long aa sits on it.
The tone is computed, not written
In Thai the same syllable said with another tone is another word. The tone is never written as a letter: it is computed from the spelling, from three things. First, the consonant class: middle, high or low, fixed for each consonant. Second, whether the syllable is live or dead. A live one ends in a long vowel or in n, m, ng, y, w. A dead one ends in a stop or a short vowel. Third, the tone mark, if there is one.
With no mark, the middle class gives an even mid tone on a live syllable. The two strokes of ้ change it — and how, depends on the consonant's class. That is why the class is not theory: without it the mark ่ cannot be read at all.
Two signs for "ai"
The diphthong ai has two spellings. ไ is "ai for everything else": ไป, pai, to go. ใ is the sign "in twenty words". There really are exactly twenty, and Thai schoolchildren learn the list by heart. You do not need it at the start: recognizing the sign is enough.
Both stand to the left of the consonant, although the sound comes after it. In ใจ the ใ is written first, then จ, and the whole thing reads jai. In ไม่ — the negation mai — the same ไ plus the one-stroke mark ่.
Vowels written in front of the consonant
Three signs — เ, แ, โ — stand to the left of the consonant and are read after it. This is the first thing the eye has to get used to. เก้า is spelled e + k + tone mark + aa and read kao, with a falling tone.
Next to them works า in its wrapping role: เ + consonant + า assemble the diphthong au — เขา, khao. The right half of this pair is the same long า that stands to the right of ก in กา.
ห — the invisible letter
In front of another consonant ห makes no sound of its own. It lifts the pair into the high class, and the tone is computed from it. หนอน, "worm", reads non: the sound comes from น, the class from ห.
Why bother: the low class runs out of tone readings of its own, and ห fixes that by raising the whole syllable. In น้ำ, "water", there is no ห — the tone is counted from the low-class น and the two-stroke mark.
Live and dead syllables: what final consonants do
Final consonants follow their own rules, and a letter at the end often changes its sound. ร and ล read n: อาหาร is ahaan. ว shrinks to a quick o or u: ข้าว is khao. And บ, ด, ป close without any release: จับ is jap, lips shut, no puff.
A syllable ending in a long vowel or in n, m, ng, y, w is called live. One ending in a stop or a short vowel is dead. The split matters when there is no tone mark: then live and dead syllables read differently. With a mark, only the consonant class counts.
Pali and Sanskrit: the spare letters
The seven spare letters are doubles: ฎ sounds like ด, ฏ like ต, ฐ like ถ. ฑ, ฒ and ธ sound like ท, and ฆ like ค. Thai took them from Pali and Sanskrit to spell loanwords faithfully. Sound and class stay the same; only the spelling remembers where the word came from.
In live words they are rare, and recognizing them takes one habit: "looks like a frequent letter, reads the same". One exception — ท is not a spare at all but the most frequent th of the language.
Rare and obsolete
These signs barely appear in live speech. ฅ and ฃ were retired decades ago and survive in old texts. ฬ is the Pali-Sanskrit double of ล. ฤ and ฤๅ pack a consonant and a vowel into one sign: rue and long ruue. ฦ and ฦๅ only keep their place in the table, as on Thai school posters.
You need them for exactly one thing: not stopping at them in a text. Nobody will write you a word with ฅ today.
| sign | what it is |
|---|---|
| ฅ | like ค; retired from use |
| ฃ | like ข; retired from use |
| ฬ | like ล; Pali-Sanskrit |
| ฤ ฤๅ | rue and long ruue; alive in words like ฤดู |
| ฦ ฦๅ | absent from live words; kept in the tables for completeness |
The four tone marks: the full table
There are four tone marks, and one rule covers them all: a mark does not name a tone — it recomputes the tone from the consonant class. The same single stroke gives a low tone on the middle and high classes, and a falling tone on the low class. The marks ๊ and ๋ never go on the high or low class. A high-class consonant reaches the rising tone without them.
In the table, the "no mark" column is for a live syllable; the columns with marks hold for any syllable. A dead syllable with no mark reads low on the middle and high classes. On the low class it reads high after a short vowel and falling after a long one.
| class | no mark | one stroke ่ | two strokes ้ | three ๊ | hook ๋ |
|---|---|---|---|---|---|
| middle | mid | low | falling | high | rising |
| high | rising | low | falling | — | — |
| low | mid | falling | high | — | — |
What order to take the characters in
The writing course is split into 23 steps: one step is one lesson, a few characters at a time. Nobody takes the whole script at once out of mercy: 67 signs in an evening stay in memory for exactly that, an evening.
- Studying a little every day gets more into your head than spending the same total time in one sitting.checked many timesDonovan & Radosevich, 1999, Journal of Applied Psychology 84(5) · 63 studies compared, difference d = 0.46 — a sizeable figure for a learning effect.
- It is better to test yourself the next day than at the end of the same session. That is why a word comes back to you tomorrow.checked many timesAdesope, Trevisan & Sundararajan, 2017, Review of Educational Research 87(3) · g = 0.82 when tested a day or two later, against 0.56 on the same day.
Frequently asked
How many characters do you need to learn to read in Thai?
67 signs. The writing course covers them all, plus 4 signs that do not count as letters: อ่, อ้, อ๊ and อ๋. After that a word stops being a picture — even when its meaning is still unknown.
What to learn first: letters or words?
Letters. A word in an unfamiliar script cannot be read at all, and a “word — translation” card tells you no more than a picture does.
How long does it take to learn to read in Thai?
One step a day — 23 days. That is about recognizing characters, not understanding: you will start reading aloud before you understand what you read.