The official national language, spoken by almost 100 per cent of the population is, THAI, classified by linguists as belonging to a Chinese-Thai branch of the Sino-Tibetan family. It is a tonal language, uninflected, and predominantly monosyllabic. Most polysyllabic words in the vocabulary have been borrowed, mainly from Khmer, Pali or Sanskrit. Dialects are spoken in rural areas. Principal other languages are Chinese and Malay. English, a mandatory subject in public schools, is widely spoken and understood, particularly in Bangkok and other major cities.