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.

The Thai language is liberally sprinkled with words from Pali and Sanskrit (the classical languages, respectively, of Theravada Buddhism and Indian Hinduism). Written Thai employs an alphabet of 44 consonants and 32 vowels that combine to form syllabic sounds.

Thai is a tonal monosyllabic language. The same word can be said in five different ways - normal or middle tone, high, low, rising and falling. In Thai the meaning of single syllable may be alter in five different tones.