The people of Vietnam speak Vietnamese which is a tonal monosyllabic Mon–Khmer language as an official national language. In its early history, Vietnamese writing used Chinese characters. In the 13th century, the Vietnamese developed their own set of characters called Chữ nôm. The celebrated epic Đoạn trường tân thanh (Truyện Kiều or The Tale of Kieu) by Nguyễn Du was written in Chữ nôm. During the French colonial period, Quốc ngữ, the romanized Vietnamese alphabet used for spoken Vietnamese, which was developed in 17th century by Jesuit Alexandre De Rhodes and several other Catholic missionaries, became popular and brought literacy to the masses.
Various other languages are spoken by several minority groups in Vietnam. The most common of these are Tày, Mường, Cham, Khmer, Chinese, Nùng, and H'Mông. The Montagnard peoples of the Central Highlands also speak a number of distinct languages. The French language, a legacy of colonial rule, is still spoken by some older Vietnamese as a second language, but is losing its popularity. Vietnam nevertheless remains a full member of La Francophonie. Russian – and to a much lesser extent German, Czech or Polish – is sometimes known among those whose families had ties with the Soviet bloc. In recent years, English is becoming more popular as a second language. English study is obligatory in most schools. Chinese and Japanese have also become more popular.