Lao or Laotian (BGN/PCGN: phasa lao, IPA: pʰaːsaː laːw) is a tonal language of the Kradai language family. It is the official language of Laos, and also spoken in the northeast of Thailand, where it is usually called the Isan language. Being the first language of the Lao people, Lao is also an important second language of ethnic groups in Laos and in Isan. Lao, like all languages in Laos, is written in an abugida script. Although there is no official standard, the Vientiane dialect has become the de facto standard.