This letter is not well-supported by fonts and is often typed as either o· (using the interpunct), o• (using the bullet), oo, or ou. Because Taiwanese is a tonal language the standard letter without a diacritic represents the vowel in the first tone, the other four possible tone categories require one of the following four tonal symbols to be written above it. * Ó͘ ó͘ (second tone) * Ò͘ ò͘ (third tone) * Ô͘ ô͘ (fifth tone) * Ǒ͘ ǒ͘ (sixth tone) * Ō͘ ō͘ (seventh tone)

This letter is not well-supported by fonts and is often typed as either o· (using the interpunct), o• (using the bullet), oo, or ou. Because Taiwanese is a tonal language the standard letter without a diacritic represents the vowel in the first tone, the other four possible tone categories require one of the following four tonal symbols to be written above it. * Ó͘ ó͘ (second tone) * Ò͘ ò͘ (third tone) * Ô͘ ô͘ (fifth tone) * Ǒ͘ ǒ͘ (sixth tone) * Ō͘ ō͘ (seventh tone)