A diacritic – also diacritical mark, diacritical point, diacritical sign, or accent – is a glyph added to a letter or basic glyph.
Some diacritical marks, such as the acute (´) and grave (`), are often called accents. Diacritical marks may appear above or below a letter, or in some other position such as within the letter or between two letters.
The main use of diacritical marks in the Latin script is to change the sound-values of the letters to which they are added.
The usual diacritics used in the French language are the acute (⟨´⟩, accent aigu), the grave (⟨`⟩, accent grave), the circumflex (⟨ˆ⟩, accent circonflexe), the diaeresis (⟨¨⟩, tréma), and the cedilla (⟨¸ ⟩, cédille).
- Acute accent or accent aigu (é): over e, indicates uniquely the sound /e/.
- Grave accent or accent grave (à, è, ù): over a or u, used primarily to distinguish homophones: à (“to”) vs. a (“has”), ou (“or”) vs. où (“where”; the letter ù is used only in this word). Over an e, indicates the sound /ɛ/.
- Circumflex or accent circonflexe (â, ê, î, ô, û): over a, e and o, indicates the sound /ɑ/, /ɛ/ and /o/, respectively. Most often, it indicates the historical deletion of an adjacent letter (usually an s or a vowel): fête < feste, sûr < seur. It has also come to be used to distinguish homophones: du (“of the”) vs. dû.
- Diaeresis or tréma (ë, ï, ü, ÿ): over e, i, u or y, indicates that a vowel is to be pronounced separately from the preceding one: naïve, Noël.
- Cedilla or cédille (ç): under c, indicates that it is pronounced /s/ rather than /k/. The cedilla is only used before the vowels a, o or u, for example, ça /sa/; it is never used before the vowels e, i, or y, since these three vowels always produce a soft /s/ sound (ce, ci, cycle).
Diacritics are often omitted on capital letters, mainly for technical reasons. Also, diacritics have no impact on the alphabetical order.
Many people believe diacritics to be unnecessary, and, for example, they are usually ignored in word games like crosswords or Scrabble.
However, the Académie française confirms that “in French, the accent has full orthographic value”.