The Thai tone rules, in one table

Thai has five tones, and a tone belongs to a word in the same way a vowel does. Change the pitch and you have said a different word, not the same word in a different mood. The clearest demonstration uses one syllable, maa. มา (maa) is to come. ม้า (máa) is a horse. หมา (mǎa) is a dog. Same m sound, same vowel, three unrelated words. หมา carries a silent ห in front — it is there only to make the tone rising. Standing at a market stall, a vendor who hears the wrong pitch does not hear you being emphatic. They may hear a different word, and wait for the rest of the sentence to make sense of it — though in a market, with the fruit already in your hand, context usually rescues you. The five tones are mid, low, falling, high and rising. Mid sits level at your ordinary speaking pitch and does not move. Low sits below your ordinary pitch. Textbooks call it level, and in careful speech it drifts a little downward; what matters is that it starts low, rather than sliding down from your normal pitch the way an English speaker's first attempt usually does. Falling starts high and drops away, close to the way you say "no" when you are refusing something firmly. High starts above your ordinary pitch and pushes upward, with a tightness in the throat. Rising dips first and then climbs, which is why it sounds to an English ear like a question. The first table below names all five and gives you a word for each. Four things decide the tone of a written syllable: the class of the initial consonant, whether the syllable is live or dead, the length of the vowel, and the tone mark, if there is one. One complication sits on top of that. In a two-syllable word with an unwritten vowel, the class of the first consonant carries over to the second syllable: ขนม is khà-nǒm, rising on the second syllable, because of the high-class ข and not the low-class น. The same happens in ถนน (thà-nǒn) and ตลาด (dtà-làat). The rules cover almost everything else, but a few very common words are genuinely irregular and have to be learned as they are — ก็ is said gâw, though its spelling points to gò, and น้ำ is written with the short ◌ำ but said long. A live syllable ends in a long vowel, or in one of the continuing sounds m, n, ng, y or w. A dead syllable ends in a p, t or k stop, or in a short vowel with nothing after it. The distinction is not arbitrary. A dead syllable is cut short, and an unmarked one never comes out mid or rising: a mid- or high-class initial gives low, a low-class initial gives high with a short vowel and falling with a long one. Add a tone mark and a dead syllable can take any tone — ล่ะ is lâ, จ๋ะ is jǎ. With no tone mark at all, the consonant class and the shape of the syllable do all the work. มา (maa) has a low-class initial and a live syllable, so it is mid. ขาว (khǎao, white) has a high-class initial and a live syllable, so it is rising. นก (nók, bird) is low class, dead, short vowel, so it is high. มาก (mâak, a lot) is low class, dead, long vowel, so it is falling. The third table sets out every combination, for syllables read on their own initial consonant. Thai has four tone marks, written above the initial consonant — or, where the initial is a cluster or a silent leading ห or อ, above the last letter of that group: in หน้า the mark sits over น, not over ห. A tone mark does not name a tone. The marks are named after tones — thoo is the Thai name of the falling tone — so learners assume the mark announces the answer. It does not. It tells you the tone only once you know the class of the consonant underneath it. Máai èek on the mid-class ป gives ป่า (bpàa, forest), a low tone. The same mark on the low-class ค gives ค่า (khâa, a fee or a value), a falling tone. Máai thoo on the high-class ข gives ข้าว (khâao, rice), falling; the same mark on the low-class น gives น้ำ (náam, water), high. The other two marks are found almost only on mid-class consonants, where they give high and rising: โต๊ะ (dtó, table) and เดี๋ยว (dǐao, in a moment). This is why the three classes are not a detail you can come back to later; they are the first question, and the mark is the second. They are set out at Thai consonant classes. If pitch is already carrying the word, how do you sound surprised, or annoyed, or gentle? Thai does it in ways that leave the tones intact. The whole utterance moves up or down as a block, so the relative shape of each tone survives while the register changes: an excited speaker sounds like a recording played higher, not like someone adding question marks to individual words. Vowels are stretched, and volume and speed change. And final particles do much of the work English does with intonation, including the question particle at the end of a sentence, which is why your voice does not need to rise there. Putting an English question rise on the last word of a Thai sentence is a habit worth breaking in your first month, because it changes that word. Are Thai tones harder than Mandarin's? Honestly, the tones themselves are not. Five instead of four is a small difference, and a Thai word keeps its citation tone in most positions: there is nothing like Mandarin's third-tone sandhi, where a tone shifts because of the tone beside it. Unstressed function words do flatten in fast speech, and emphatic reduplication changes a tone outright — ดี (dii) becomes ดี๊ดี (díi dii). What is harder is reading them. Mandarin learners are handed the tone in pinyin, marked above the vowel. No Thai letter or mark names a tone on its own; the script gives you the ingredients and you work it out, and the romanisation on the street signs and menus around you marks nothing at all. The difficulty in Thai is not in the mouth. It is on the page. Tones or the alphabet first? Both, in this order. Spend your first few weeks training your ear and your voice on the five tones with no writing at all, because you cannot apply a rule to a sound you cannot yet hear. Then start the alphabet, and learn every consonant with its class attached from the first day. Learners who postpone the script end up with hundreds of words whose pitch they half-remember and no way to check one. Learners who skip the ear training can calculate a tone in four seconds and still cannot say it. For practice, work with minimal pairs out loud, from a recording, in both directions: hearing them apart and saying them apart are separate skills, and neither arrives with the other. Move into short phrases as soon as isolated words are steady, because tones are much harder inside the rhythm of a sentence than alone. Record yourself and compare with the recording rather than with your memory of what you just did. And ask a Thai friend to correct you explicitly, because many people will just work out what you meant and say nothing rather than interrupt you, especially someone you have only met once. Drill the marks against the classes at tone marks and reading, and train the ear at listening for tones.