The official and dominant language is Lao, a tonal language of the Tai linguistic group. However, only slightly more than half of the population can speak Lao. The remainder, particularly in rural areas, speak ethnic minority languages. The Lao alphabet, which evolved sometime between the 13th and 14th centuries, was derived from the ancient Khmer script and is very similar to Thai, and easily understood by readers of Thai script.[106] Languages like Khmu and Hmong are spoken by minorities, particularly in the midland and highland areas. A number of Laotian sign languages are used in areas with high rates of congenital deafness.
French is still commonly used in government and commerce and over a third of Laos' students are educated through the medium of French with French being compulsory for all other students. Throughout the country signage is bilingual in Laotian and French, with French being predominant. English, the language of the Association of Southeast Asian Nations (ASEAN), has become increasingly studied in recent years.