Modifier Letter Macron

Use ˉ as its own character, not as an attached accent. In Bopomofo (Zhuyin), the phonetic symbols for Mandarin syllables, this macron is a tone mark stored after the syllable’s letters. Phonetic notation may place tone marks before or after a syllable; a layout can display one beside it. For a bar that attaches to a vowel, use combining macron ◌̄.

ˉ, ¯, and ◌̄ share a bar shape but behave differently: ˉ is a spacing tone mark, ¯ is a separate overbar, and ◌̄ attaches to the preceding letter.

Does a macron mark a long vowel?

The system decides: Latin marks length; phonetic notation can mark pitch. A bar over a Latin vowel marks long quantity in teaching; in phonetic notation ˉ marks a high, level tone, and Bopomofo assigns it to Mandarin’s first tone.

Latin vowel-length marks have older roots. Roman inscriptions used doubled vowels around 134–78 BC and, in Sulla’s time, an apex (a small mark over a vowel) to show long quantity; these were earlier conventions, not this exact character. A later account credits Greek scholar Aristophanes of Byzantium with inventing signs for pitch and vowel length, but that account’s history is doubtful.

Modern Latin dictionaries and textbooks add a bar over vowels to guide pronunciation and metre; it is an editorial aid, not ordinary unmarked spelling. Taiwan’s Ministry of Education describes Bopomofo as a way to spell a Mandarin syllable’s starting sound, ending, and tone; its first version was created in 1913 and released in 1918.