Tonality

Vietnamese is an Austroasiatic language written using a highly modified form of the Latin alphabet. Its modern writing system, known as Quốc Ngữ, was developed during the 17th century and later standardized to replace earlier Chinese-based writing systems.

Unlike standard Latin alphabets, Vietnamese uses an extensive system of diacritics to represent both vowel quality and tonal variation. Each syllable carries one of several tones, and these tones are marked directly on vowels using accent marks.