Dialects
| Dialect | Lao Provinces | Thai Provinces |
| Vientiane Lao | Vientiane, Vientiane Capital Prefecture, Bolikhamsai | Nong Bua Lamphu, Chaiyaphum, and parts of Nong Khai, Yasothorn, Khon Kaen, and Udon Thani. |
| Northern Lao | Luang Prabang, Sainyabuli, Oudomxay. | Loei and parts of Udon Thani and Khon Kaen. |
| Northeastern Lao/Tai Phuan | Xiangkhoang and Houaphanh. | Parts of Sakon Nakhon, Udon Thani. |
| Central Lao | Savannakhet and Khammouan. | Mukdahan and parts of Sakon Nakhon and Nong Khai. |
| Southern Lao | Champasak, Salavan, Sekong, and Attapeu. | Ubon Ratchathani, Amnat Charoen, and parts of Yasothorn, Buriram, Si Sa Ket, Surin and Nakhon Ratchasima |
| Western Lao | Kalasin, Maha Sarakham, and Roi Et. |
In addition to the dialects of Lao, numerous closely related languages (or dialects, depending on the classification) are spoken throughout the Lao-speaking realm in Laos and Thailand, such as the Nyaw, Phu Thai, Saek, Lao Wieng, Tai Dam, Tai Daeng, etc. These Tai peoples are classified by the Lao government as Lao Loum (ລາວລຸ່ມ) or lowland Lao. Lao and Thai are also very similar and share most of their basic vocabulary, but differences in many basic words limit inter-comprehension.
Read more about this topic: Lao Language