In phonetics, the horn is a diacritic mark attached to the top right corner of the letters o and u in the Vietnamese alphabet to give ơ and ư, unrounded variants of the vowel represented by the basic letter.
The main usage of a diacritic is to change the phonetic meaning of the letter, but the term is also used in a more general sense of changing the meaning of the letter or even the whole word.
Diacritics can be used for emphasis (érg koud for very cold) or for disambiguation between the numeral one (één appel, one apple) and the indefinite article (een appel, an apple).
Vietnamese uses the horn for the letters ơ and ư; circumflex for the letters â, ê, and ô; breve for the letter ă; and a bar through the letter đ.
For the instrument—i.e., French horn —see horn (instrument).
A horn is a hollow, pointed projection of the skin of various animals.
In phonetics, the term horn is used for a diacritic mark attached to the top right corner of the letters o and u in the Vietnamese alphabet to give 417; and ư, unrounded variants of the vowel represented by the basic letter.