Combining Acute Tone Mark

Use U+0301 for new Vietnamese text. U+0341 is canonically equivalent to U+0301, so it does not mark a different tone. Unicode discourages it for Vietnamese; if it appears in an older file, read it as the same acute tone sign, not an extra mark.

This mark writes sắc, the Vietnamese tone usually described as rising.

Where does the Vietnamese acute mark come from?

It belongs to the Latin-script quốc ngữ tradition. Jesuit missionaries developed and used this Latin spelling system in the early 17th century to study Vietnamese and prepare dictionaries, grammars, and catechisms. Portuguese spelling conventions influenced it, and several contributors shaped it over time. The tone signs let Latin letters record distinctions in Vietnamese speech.

Francisco de Pina's Manuductio, a grammar describing Vietnamese tones, is dated before 1623; its surviving copy was made around 1745. Alexandre de Rhodes published a Vietnamese dictionary and grammar in 1651, building on Pina's account and other missionaries' work. In their descriptions, sắc was an acute, rising tone. Speakers from different regions may realize its contour differently, while the written tone category stays the same. The spelling tradition predates Unicode; U+0341 is a later encoded form.

Why can the acute sit beside a circumflex?

Vietnamese fonts can shift it sideways to make room. A Vietnamese vowel can carry a letter-shape mark, such as a circumflex, breve, or horn, and a tone mark on the same letter.

A Vietnamese-aware font may place the acute beside the shape mark instead of stacking both directly above the vowel. Exact placement varies by font; the spelling and tone do not change.