Thai doesn’t write tones directly. Instead, each syllable’s tone is derived from four things: the class of its first consonant (that’s why you learned the classes), whether the syllable is live or dead, the vowel length, and any tone mark. Learn the rules and you can read the tone of any word you meet.
A syllable is live if it can ring on: it ends in a long vowel or a sonoranti sound — m, n, ng, y, w (มา, นอน, ยาว). It’s dead if it cuts off short: a short open vowel, or a p / t / k stopi at the end (จะ, รัก, มาก). Note the four self-contained vowels ◌ำ ใ◌ ไ◌ เ◌า end in m / y / w sounds, so they’re always live.
Marks sit above the initial consonant. What they produce depends on the class — the names are just the Thai numbers 1–4.
Find the class row, then the column that matches the syllable. Tap any example to hear the tone. Spoken out loud, the low-class row reads: low + live = mid · low + dead-short = high · low + dead-long = falling · อ่ = falling · อ้ = high — and likewise for the other rows.
| No mark — live | No mark — dead, short | No mark — dead, long | + อ่ | + อ้ | + อ๊ | + อ๋ | |
|---|---|---|---|---|---|---|---|
| Mid class | midcrow | lowwith | lowfrom | lowold | fallingcan | hightable | risingsweetie! |
| High class | risingleg | lowto drive | lowtorn | lownews | fallingrice | — | — |
| Low class | midto come | highto love | fallingvery | fallingnot | highhorse | — | — |
Silent ห — a leading ห before a group-2 sonorant isn’t pronounced; it just lends its high class, unlocking tones the sonorant can’t make alone: หมู mǔu (pig), หนู nǔu (mouse), แหวน wǎen (ring).
Silent อ — the same trick with อ lending mid class, in exactly four words: อย่า อยู่ อย่าง อยาก (yàa, yùu, yàang, yàak).
That’s the whole system. Clusters next — one last spelling pattern to apply it to — then the reading quiz makes it reflex.