The Thai and Lao languages both belong to the Tai language family and are closely related. Different aspects of the languages are compared here.

Vocabulary: Possibly 70 percent of the words in Thai and Lao are the same (there hasn't been a count), but many common words are different including pronouns, negatives, wh- question words, and vocabulary like "walk", "little", "run", "look", "book", and "bottle". Some words may be the same but are used in different ways in the two languages. For example, heuan, the general word for "house" in Lao also means "house" in Thai but is only used formally. High level words are usually the same in the two languages because they were taken from Sanskrit and Pali.

Sentence Structure: The grammar of the two languages is almost identical so structures like comparatives, tenses, and the use of conjunctions are the same. There are some small differences, especially in the formation of several types of questions: "Have you...yet?" is formed with reu yang? in Thai but with laeo baw? in Lao. Negative questions like "You're not going?" are Mai pai reuh? in Thai but Baw pai baw? in Lao. (Baw in Lao is the equivalent of mai in Thai.)

Pronunciation: Lao has one sound - ny - which isn't present in Thai. "Not yet" is nyang in Lao but yang in Thai, and "woman" is phoo nying in Lao and phoo ying in Thai. Tones on words vary throughout the region but follow the same system.

Mutually unintelligible: Despite being so similar, it's not possible to understand Lao if you speak only Thai and vice versa. You will hear many words you know and may understand some complete sentences, but there are enough differences, especially in basic vocabulary, to make the two languages mutually unintelligible. Because high level words are mostly the same it's easier for a Thai speaker to understand high-level Lao than informal Lao (and vice versa).

Speaking styles: Laotians speak in a straightforward way without adding the polite words (ka/krup) common in Thai and without the elaborate word play that some Thais like to use. Lao may sound more formal than Thai because Laotians tend to speak in complete sentences and include the pronouns "I" and "you". This is in contrast to Thai where informal conversation is abbreviated in a cute, fun way, and pronouns are usually omitted. (In both Thai and Lao words can be omitted from sentences, and the more complete a sentence is the more formal it sounds.)

Writing: Lao and Thai have similar alphabets and most of the letters are the same. Sentences are written in the same way: from left to right and with no spaces between words. Thai writing remains closer to Sanskrit/Pali and has many more consonants than Lao (for example, four letters with an "s" sound). Lao was revised to be written phonetically by law so that it could be read more easily by non-Lao ethnic groups, and many of the extra consonants were eliminated and the spelling rules simplified (there are only two letters with an "s" sound). A person who can read Thai can learn to read Lao in a few hours, but a Lao reader needs to learn 20-odd new consonants, plus some complicated spelling rules, to be able to read Thai.

Sociolinguistics of Thai and Lao

Dominant Languages: Thai and Lao are just two of the many Tai languages in the four-country region of Thailand, Laos, Myanmar, and Vietnam. All of the Tai languages have similar vocabulary, grammar, and tone structure. Thai and Lao have been studied the most of all the Tai languages. There are few books or academic papers on Shan, Thai Dam, Phuan, and other Tai languages.

Thai and Lao became the dominant languages in their respective countries for the same reason that any language becomes dominant: the ethnic group that speaks it becomes politically dominant and their language is held up as the standard. Other languages continue to be spoken but are considered regional or outlying languages, and may also be regarded as inferior by the dominant group. As a saying goes: "A language is a dialect with an army".

The histories of Thai and Lao follow this pattern. Central Thais (or Siamese) became the dominant ethnic group along the Chao Phra Ya River basin in the south while ethnic Laotians dominated the Mekong River basin in the north. The languages of other groups, both Tai and non-Tai, became minor languages or "regional dialects" as they're called in Thailand.

A Short History of Isan: The native people of Northeastern Thailand are ethnic Laotians and the language they speak is Lao, officially called "Isan" or "Thai-Isan". The name change from "Lao" to "Isan" came in the 70's when the Lao PDR was becoming Communist. A war raged along the Mekong River border in the 70's with some villagers on the Thai side fighting with the Communists, and the Thai army fighting battles to keep the area part of Thailand. Not wanting Northeasterners to identify with or become sympathetic to Communist Laos because of their shared ethnicity, the Thai government began a campaign to change the self-identity of Northeastern people from "Lao" to "Isan". The campaign worked so well that at the present time some Northeasterners don't know their language is the same as that spoken in the Lao PDR (although some Isan people still call themselves and their language "Lao").

Where is Lao/Isan Spoken?- In Thailand, most Isan people are bilingual in Lao/Isan and Thai. They use Thai in school, government offices, in commercial areas of Isan towns, and when living in other parts of Thailand, but use Lao or Lao mixed with Thai at home. Not everyone in NE Thailand can speak Lao, though. The language or languages a person speaks depends on his or her family background: people born in traditional Lao/Isan families usually speak the language fluently while Thai families who have moved to Isan from Central Thailand speak Thai and know how to speak Lao/Isan only if they have close contact with Isan people and a need or desire to learn the language.

Some Central Thais living outside of Isan are able to speak Lao/Isan, or at least know some words and phrases. These people have usually lived in Isan or Laos, are married to a Lao or Isan person, or have worked or gone to school with people from Isan and developed an interest in the language.

Who speaks Thai in Laos? - In the Lao PDR, most Laotians living near the border can understand Thai, although they may not speak it well because their understanding comes from listening to Thai TV and radio. In areas of Laos further away from the border the number of people who understand Thai decreases because a satellite dish is needed to pick up Thai TV. Ethnic Laotian enjoy Thai TV and music because the two cultures are so similar. Laotians who speak Thai may have studied or worked in Thailand, be married to a Thai, come from a Thai-Lao family, or travel to Thailand for commercial trading.


Attitudes: Before the economic and educational boom that began in the 80's, Isan people were considered rustic by Central Thais, but the increase in contact within Thailand and the general development of the country has caused many Thais to have a more pluralistic approach to ethnic relations. At present it's rarer to see Central Thais looking down on Isan people, although this was very overt behavior in the past. Respect for Lao/Isan language culture (and also Northern and Southern Thai language and culture) has increased partly by the active promotion of non-Central Thai cultures by the Thai government and universities.


The Future of Lao: When Laos opened to the non-communist world in 1990 there was a lot of fear that the Lao language would disappear as Thailand took over Laos economically and culturally. This hasn't happened, in fact, China has more economic influence in Laos than Thailand. At this time it looks like the Lao language will remain strong in the Lao PDR for these reasons:

1. The Lao government doesn't allow Thai to be used in the media and in schools.
2. Newspapers, books, and TV and radio programs in Lao language are distributed throughout the country.
3 .Laotian people consider themselves different from Thais. They identify strongly with their culture and language, are proud of it and want to preserve it.

In practice, the two languages are so close that Laotians pick up Thai vocabulary easily, especially slang, pop words, and coined words dealing with modern concepts. The time is a long way off, though, when the majority of Laotians are using mai instead of baw.

It isn't so certain if Isan can maintain its language. It's possible that Isan people will be assimilated with Central Thais as people move around and intermarry more. The time may come when Isan is urbanized with mechanized sticky rice farming; when there are no more pakamas and village temple fairs and the memory of the culture is maintained in old songs and broadcasts from the Lao PDR. On the plus side Isan universities are active in promoting Isan language and cultural studies. There are cultural exchanges with the Lao PDR and many Thai tourists travel to Laos. In the future the Lao PDR may have a strong role in keeping Lao culture alive in Isan.

 (The above are personal views based on my experiences living in both Thailand and Laos. Please send comments to the email address on the HOME page - J. Higbie.)