Lao is the official language of Laos and the native language of most Lao people.
Lao belongs to the Kra–Dai language family and is especially closely related to Thailand’s Thai language. The two languages share substantial vocabulary and grammatical features, although they use different standard writing conventions and have distinct national identities.
Lao is written in the Lao script, an abugida historically related to the Old Khmer script. Written Lao does not normally mark word spaces; spaces generally separate phrases or clauses instead. Tone is important in Lao, as it is in many languages of mainland Southeast Asia.
Lao is also spoken by communities outside Laos, particularly in northeastern Thailand, where related varieties are often grouped with the Lao language continuum. A common mix-up is to call Lao simply “Laotian”; “Lao” is the standard name for both the language and, in many contexts, the people or culture associated with Laos.