Lao and Thai are both Tai languages, closely related and heavily overlapping. Their scripts descend from the same Khmer-derived source and look similar without being identical. The relationship is roughly that of two close dialects that became separate national standards.
Comprehension runs one way
Lao speakers generally understand Thai well. Thai speakers understand less Lao. The reason is exposure rather than structure: Thai media has been widely available in Laos for decades, while Lao media has little presence in Thailand.
The exception is Isan, spoken across northeastern Thailand by a large population. Isan is linguistically very close to Lao — closer to it than to standard Thai — so Isan speakers follow Lao without difficulty.
Lao reformed its spelling
| Thai script | Lao script | |
|---|---|---|
| Consonant letters | 44 | 27 |
| Silent letters | many, from Sanskrit and Pali | largely removed |
| Spelling principle | etymological | phonetic |
| Duplicate letters for one sound | several | few |
Thai retains multiple letters for identical sounds because they preserve the origins of borrowed words — eleven different letters can close a syllable as -t. Lao removed most of that redundancy, so the script maps far more directly onto pronunciation. For a learner this makes Lao easier to read, though Thai has far more material available.
Neither language uses spaces between words. Both use them at phrase and sentence boundaries instead, in the manner inherited from Indian-derived scripts. Segmentation relies on syllable structure and on recognising common function words — a skill that transfers directly from one language to the other.
Shared vocabulary, different high-frequency words
| English | Lao | Thai |
|---|---|---|
| to eat | kin | kin |
| water | nam | nam |
| to go | pai | pai |
| hello | sabaidee | sawatdee |
| thank you | khop chai | khop khun |
| what | nyang | arai |
The core is shared; the greetings and a set of very frequent words diverge. That distribution is typical — the everyday words a learner meets first are precisely the ones most likely to differ, which exaggerates the apparent distance.
Tones are structural, not written directly
Both languages determine tone from a combination of factors rather than from a single mark:
| Factor | Effect |
|---|---|
| Consonant class | high, mid or low class sets the base |
| Vowel length | short and long syllables behave differently |
| Final consonant | a stop closes the syllable and restricts tone |
| Tone mark | modifies the result when present |
This means tone must be computed from the spelling rather than read off it — a rule system to learn rather than a diacritic to notice. It is the main reason both scripts take time even after the letters are known.
Grammar is analytic and shared
| Feature | Both languages |
|---|---|
| Word order | subject-verb-object |
| Verb conjugation | none |
| Grammatical gender | none |
| Plural marking | optional |
| Classifiers | required when counting |
| Adjective position | after the noun |
Both also use particles at the end of sentences to mark politeness and attitude, and both have register systems influenced by Pali for formal and religious vocabulary.
Which to learn
Thai has vastly more courses, dictionaries and media. Lao has a simpler script and a smaller learning ecosystem. Learning either gives substantial access to the other, with the transfer easier from Thai to Lao because the harder orthography comes first.
If Laos is the goal, learn Lao directly — the simplified script pays off immediately, and Thai remains largely comprehensible afterwards through the shared core.
Look up Lao offline
The free English-Lao Dictionary covers everyday vocabulary in Lao script, working with no connection required.
Open the dictionary appFrequently asked questions
Can Lao and Thai speakers understand each other?
Asymmetrically. Most Lao speakers follow Thai well, largely through decades of exposure to Thai television, radio and music. Thai speakers without that exposure understand considerably less Lao, though speakers of Isan, the closely related language of northeastern Thailand, manage easily.
Is Lao script easier than Thai script?
Generally yes. Lao underwent spelling reforms that made the script more phonetic, reduced the number of letters, and removed most silent letters retained from Sanskrit and Pali etymology. Thai kept the historical spellings, so its orthography is more complex.
How many tones does Lao have?
Vientiane Lao is usually analysed as having six tones, though the count varies by dialect. Tone is determined by a combination of the consonant class, the vowel length, the final consonant and any tone mark — the same system Thai uses.