The Thai language: what every learner should know

Thai at a glance

• Name: Thai, ภาษาไทยpaa-sǎa tai in Thai. Older English sources call it Siamese; the country was renamed from Siam to Thailand in 1939.
• Speakers: about 71 million, of whom around 27 million speak it as their first language (Ethnologue's 2024 figures). Most of the rest grew up with Isan, Northern Thai, Southern Thai or another language at home and use standard Thai at school, at work and with strangers.
• Where: Thailand, where it's the national language of government, schools and the media, plus small Thai-speaking communities in neighbouring countries and Thai communities abroad.
• Family: Kra-Dai, in the Southwestern Tai branch, alongside Lao and Shan.
• Script: its own alphabet of 44 consonants, with vowel signs around them and four tone marks.
• Tones: five: mid, low, falling, high and rising.
• Grammar: subject, verb, object, like English, but with no conjugation, plurals, articles or grammatical gender.
• Official body: the Royal Society of Thailand sets spelling and publishes the official dictionary.
• National Thai Language Day: 29 July. It marks a 1962 discussion about the Thai language at Chulalongkorn University in which King Bhumibol took part, and was made official in 1999.

Where Thai comes from

Thai is a Tai language, part of the Kra-Dai family, whose relatives are spoken in an arc from southern China through Laos and northern Vietnam to Thailand. Linguists trace its ancestors to what is now southern China. A study of ancient Chinese loanwords by the Thai linguist Pittayawat Pittayaporn suggests that the Southwestern Tai languages, the branch that includes Thai and Lao, began spreading south between the 8th and 10th centuries.

The Tai kingdom of Sukhothai rose in the 13th century and gave Thai its oldest traditional written record, the Ram Khamhaeng Inscription, dated 1292. The kingdom of Ayutthaya (1351-1767) followed, and its court absorbed so much from the Khmer of Angkor that a large share of Thai's formal and royal vocabulary is Khmer in origin. After Ayutthaya fell, the capital moved to Thonburi and then, in 1782, to Bangkok, whose speech became today's standard Thai.

Words from Pali, Sanskrit, Khmer, Chinese and English

The everyday core of Thai is native Tai: words like กินgin (eat), ไปbpai (go) and บ้านbâan (home). On top of that, every era left its layer:

• Pali and Sanskrit, through Buddhism and the court: ภาษาpaa-sǎa (language), ประเทศbprà-têet (country), อาหารaa-hǎan (food), รถrót (vehicle). These learned words are why Thai has so many long, formal words alongside its short everyday ones.
• Khmer, especially in formal and royal language: ถนนtà-nǒn (road) is one of the everyday survivors.
• Chinese, at two very different times. The numbers from two to ten, such as สามsǎam (three) and สิบsìp (ten), are ancient borrowings from Chinese, most of them older than Thai itself. Much later, Teochew immigrants brought food and family words like ก๋วยเตี๋ยวgǔay-dtǐaw (noodle soup).
• Malay: fruit like ทุเรียนtú-rian (durian).
• English, today: แท็กซี่táek-sîi, คอมพิวเตอร์kawm-piu-dtôe, ฟรีfrii, all said the Thai way, with tones.

Dialects and regional languages

Standard Thai is based on the Central Thai of Bangkok, but Thailand has four big regional varieties: Central Thai, Isan in the northeast, Northern Thai (คำเมืองkam-mueang) around Chiang Mai and Southern Thai. The Thai state calls them dialects; many linguists treat them as related languages. They share grammar and much of their vocabulary but differ in tones and in everyday words: delicious is อร่อยà-ràwy in Bangkok, ลำlam in Chiang Mai, แซ่บsâep in Isan and หรอยrǎwy in the south. Almost everyone also speaks standard Thai, which is what you should learn first. Our guide to what language is spoken in Thailand covers the regional languages, Malay, Khmer and the hill-tribe languages, and how much English you'll hear.

Thai vs Lao

Thai and Lao are the closest major relatives in the family, close enough to be partly mutually intelligible. Isan, the main language of northeast Thailand, is essentially Lao, though it's written in Thai script. The differences:

• Script: Lao has its own alphabet, a close cousin of Thai's with rounder letters and spelling that follows pronunciation more closely.
• Tones and vowels: Lao has a different tone system; Vientiane Lao is usually described with six tones.
• Everyday words: "not" is ไม่mâi in Thai and บ่bàw in Lao and Isan; "very" is มากmâak versus หลายlǎai; "to speak" is พูดpûut versus เว้าwáo; "what" is อะไรà-rai versus หยังyǎng.
• Who understands whom: people in Laos usually understand Thai well, thanks to Thai television, music and social media. Bangkok Thais find Lao harder to follow.

If you learn Thai, you'll pick up Lao much faster than a beginner would, and the reverse is true too.

The Thai script

Thai has its own alphabet, adapted from Old Khmer writing in the 13th century: 44 consonants (two no longer used), vowel signs written before, after, above, below or around the consonant, and four tone marks. Words run together without spaces, and there are no capital letters. It looks intimidating, but it's regular, and the spelling tells you the tone, which romanization can't do reliably. Our guide to the Thai writing system explains how it works and how to read your first real sign, and the free Read Thai course teaches it one letter at a time.

Five tones

Every Thai syllable has one of five tones, and the tone is part of the word:

• Mid: ไกลglai, far
• Low: ไก่gài, chicken
• Falling: ใกล้glâi, near
• High: ม้าmáa, horse
• Rising: หมาmǎa, dog

Thais do understand foreigners with imperfect tones much of the time, from context. But tones are what separate near from far, and getting them roughly right is the biggest single step from "foreigner speaking Thai words" to "someone speaking Thai". Our Thai tones page has audio for all five and a free trainer.

Thai grammar in brief

Thai grammar is where English speakers get good news. There's very little to memorise in the way of forms; the work is in word order and in small words that carry meaning.

• Verbs never change. กินgin is eat, eats, ate, eaten and eating. Time comes from context, from time words like เมื่อวานmûea-waan (yesterday) and พรุ่งนี้prûng-níi (tomorrow), or from small markers: แล้วláew (already), จะjà (will) and กำลังgam-lang (in the middle of).
• No plurals and no articles. หมาmǎa is a dog, the dog or dogs. Context, or a number, decides.
• Subject, verb, object: เขาชอบกาแฟkǎo châwp gaa-fae, "he likes coffee" (or she: เขาkǎo covers both).
• Adjectives follow the noun and work like verbs, with no "to be": อาหารอร่อยaa-hǎan à-ràwy means both "delicious food" and "the food is delicious".
• Counting uses classifiers: noun, number, then a counting word. หมาสองตัวmǎa sǎwng dtua is "two dogs", literally "dog two body". English does this too with "two cups of coffee"; Thai does it with everything.
• Questions keep the word order and add a question word, usually at the end: เผ็ดไหมpèt mǎi (is it spicy?), ไปไหนbpai nǎi (where are you going?).
• Pronouns are often dropped when the context is clear: กินข้าวหรือยังgin kâao rǔue yang (have you eaten yet?) never says "you".
• Particles at the end add mood and politeness: ครับkráp and ค่ะkâ for politeness, นะná to soften, เลยloei for emphasis.

Polite Thai: particles, pronouns and registers

Politeness is built into the language. The most visible part is the polite particle at the end of a sentence: men say ครับkráp, women say ค่ะkâ (or คะká in questions). Our guide to krap and ka explains when to use them and when to drop them.

The word for "I" also depends on who you are and who you're talking to: ผมpǒm for men, ฉันchǎn for women, เราrao among friends, and often your own nickname. On top of everyday Thai sit a formal written register and ราชาศัพท์raa-chaa-sàp, the special vocabulary used about the royal family. "To eat" is กินgin at the market, รับประทานráp-bprà-taan on a formal sign and เสวยsà-wǒei for the king. Learners only need the everyday level, with particles; Thais don't expect foreigners to use royal vocabulary.

How hard is Thai to learn?

The US Foreign Service Institute puts Thai in Category III, its "hard languages": about 44 weeks of full-time study for an English speaker to reach professional working proficiency. That's harder than Spanish or Indonesian but much less than the 88 weeks it estimates for Mandarin, Japanese or Korean.

What's easy:

• no conjugations, plurals, articles or grammatical gender
• short everyday words, often one syllable
• plenty of English loanwords
• Thais are encouraging: even a few words get a delighted เก่งจังgèng jang, "you're so good!"

What's hard:

• Tones and vowel length, which English doesn't use to change meaning.
• Sounds English lacks, such as the difference between ปbpaw (bp) and พpaw (p), or the ng sound at the start of a word.
• The script and its tone rules, a few weeks for the letters and a few months to read comfortably.
• Fast real-life speech, with dropped syllables, slang and regional accents.

For realistic time frames by goal, see our guide on how to learn Thai.

Where to start

1. Learn the sounds: spend your first week hearing and saying the five tones.
2. Learn useful chunks: greetings, thank you, numbers, ordering food and getting around, with the right polite particle.
3. Start the script early: it fixes the tones in your head.
4. Speak every day: out loud, to an app that checks your tones, then to people.
5. Listen to real Thai: graded YouTube channels, songs and Thai series.

Our free course does all five in one place, starting with Unit 1, "Hello, Thailand", and you can start without an account. If you want a word list first, our list of the 100 most common Thai words is built from real frequency data.