Isan language

Isan is a group of Lao varieties spoken in the northern two-thirds of Isan in northeastern Thailand, as well as in adjacent portions of Northern and Eastern Thailand. It is the native language of the Isan people, spoken by 20 million or so people in Thailand, a third of the population of Thailand and 80% of all Lao speakers. The language remains the primary language in 88% of households in Isan. It is commonly used as a second, third, or even fourth language by the region's other linguistic minorities, such as Northern Khmer, Khorat Thai, Kuy, Nyah Kur and other Tai or Austronesian-speaking peoples. The Isan language has unofficial status in Thailand and can be differentiated as a whole from the Lao language of Laos by the increasing use of Thai grammar, vocabulary and neologisms.Code-switching is common, depending on the context or situation. Adoption of Thai neologisms has also further differentiated Isan from standard Lao.

The Tai languages originated in what is currently known as central and southern China in an area stretching from Yunnan to Guangdong as well as Hainan and adjacent regions of northern Vietnam. Tai speakers arrived in South-East Asia around 1000 CE, displacing or absorbing earlier peoples and setting up mueang (city-states) on the peripheries of the Indianised kingdoms of the Mon and Khmer people. The Tai kingdoms of the Mekong Valley became tributaries of the Lan Xang mandala (Isan: ล้านซ้าง, RSTG: lan chang, Lao: ລ້ານຊ້າງ, BGCN: lan xang, /lȃːn sȃːŋ/) from 1354-1707. Influences on the Isan language include Sanskrit and Pali terms for Indian cultural, religious, scientific and literary terms as well as the adoption of the Pallava alphabet as well as Mon-Khmer influences to the vocabulary.