The Vietnamese language has a reputation for being fiendishly difficult to master. Its origins are still the subject of dispute - at one time thought to be a Sino-Tibetan language (because it is tonal), it is now believed to be Austro-Asiatic and related to Mon-Khmer. During the 9th century, when Vietnam was under Chinese domination, Chinese ideograms were adapted for use with the Vietnamese language. The script - chu nho ('scholar script') was used in all official correspondence and in literature until the 20th century, though whether this replaced an earlier writing system is not known.

As early Vietnamese nationalists tried to break away from Chinese cultural dominance in the late 13th century, they devised their own script, based on Chinese ideograms, but adapted to meet Vietnamese language needs. This became known as chu nom or 'vulgar script'. Therefore, while Chinese words formed the learned vocabulary of the intelligentsia - largely inaccessible to the people on the street or in the paddy field - non-Chinese words made up a parallel popular vocabulary. Since World War One the Latin-based quoc ngu script has become widely used.