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.