The official language of Vietnam is Vietnamese, which is the mother tongue of the Vietnamese people who constitute 86% of Vietnam's population, and of about three million overseas Vietnamese. And it is the second language of the ethnic minority groups in the country. It is monosyllabic, with each syllable having six different tones that can change the meaning of the word. This makes it quite difficult for new learners. Beside the official language, each ethnic minority group has its own dialect that has been used and preserved in daily life.
The Vietnamese writing system in use today is an adapted version of the Latin alphabet, with additional diacritics for tones and certain letters. The different tones are indicated by the use of accent marks. This system of writing, called quoc ngu, was created by a French Catholic missionary, Fr. Alexander De Rhodes, in the 17th century to translate the scriptures.
When France invaded Vietnam in the late 19th century, French gradually replaced Chinese as the official language in education and government. Vietnamese adopted many French terms, such as đầm (dame, from madame), ga (train station, from gare), sơ mi (shirt, from chemise), and búp bê (doll, from poupée). In addition, many Sino-Vietnamese terms were devised for Western ideas imported through the French.
However, the Romanized script did not come to predominate until the beginning of the 20th century, when education became widespread and a simpler writing system was found more expedient for teaching and communication with the general population.