Diacritic

A diacritic or diacritic(al) mark or diacritic(al) sign, in several writing systems, is a little sign added on a character, modifying slightly this character, in order to give any information about the pronunciation or, sometimes, in order to distinguish a word from another word. For instance: the character e becomes é, c becomes č, o becomes ø, s becomes ș, ω becomes ώ, и becomes й, nh becomes n·h.

A letter with a diacritic is called a modified letter.

Concerned writing systems

Diacritics may occur in most writing systems.

• Some diacritics are unique to one writing system. For instance, the diacritic called shadda, indicating that a consonant is geminate (doubled), is typical of the Arabic alphabet: ر (d) with a shadda becomes دّ (dd) .
• Several diacritics may be shared by different but resembling writing systems. It is notably the case for the Roman, the Greek and the Cyrillic alphabets, which can share the acute accent (´) and the dieresis (¨).

Examples of diacritics

Roman alphabet

• accent
  • acute accent (´): á, ć, é, ǵ, í, ń, ó, ŕ, ś, ú, ẃ, ý, ź...
  • grave accent (`): à, è, ì, ò, ù, ẁ, ỳ...
  • double acute accent ( ˝ ): ő, ű...
  • circumflex accent ( ˆ ): â, ĉ, ê, ĝ, ĥ, î, ĵ, ô, ŝ, û, ŵ, ŷ, ẑ...
• breve ( ˘ ): ă, ĕ, ğ, ĭ, ŏ, ŭ...
• caron or haček ( ˇ ): č, ď (Ď), ě, ǧ, ň, ř, š, ť (Ť), ž...
• dieresis or umlaut (¨): ä, ë, ï, ö, ü, ÿ...
• macron ( ¯ ): ā, ē, ī, ō, ū, ȳ...
• cedilla ( ¸ ): ç, ş...
• comma (,): ģ (Ģ), ķ, ļ, ņ, ș, ț...
• ogonek or nosinė ( ˛ ): ą, ę, į, ǫ, ų...
• dot
  • overdot ( ̇ ): ċ, ė, ġ, ż...
  • underdot (  ̣ ): ạ, ḍ, ẹ, ḥ, ị, ọ, ṣ, ṭ, ụ, ẓ...
  • interpunct (·): ch·, g·, l·l, n·h, s·h...
• hook or dấu hỏi ( ̉ ): ả, ɓ (Ɓ), ƈ, ɗ (Ɗ), ẻ, ƒ (Ƒ), ɠ (Ɠ), ỉ, ƙ (Ƙ), ɱ (Ɱ), ŋ (Ŋ), ỏ, ƥ (Ƥ), ƭ (Ƭ), ủ , ʋ, ⱳ, ỷ, ƴ, ȥ...
• horn or dấu móc ( ̛ ): ơ, ư...
• ring
  • ring above or kroužek ( ˚ ): å, ů...
  • ring below ( ˳ ): ḁ...
• tilde (  ̃ ): ã, ẽ, ĩ, ñ, õ, ũ...
• apostrophe (’): c’h...
• single opening quotation mark (‘): g‘, o‘...
• stroke (/): ð (Ð), đ (Đ), ħ (Ħ), ł, ø...

Greek alphabet

• accent
  • acute accent (´)
  • grave accent (`)
• perispomene, shaped like a circumflex accent ( ˆ ) or like a tilde (  ̃ )
• dieresis (¨)
• iota subscript (ͺ): ᾳ, ῃ, ῳ
• rough breathing or dasia ( ῾ )
• smooth breathing or psili ( ᾿ )

Status of modified letters

A letter with a diacritic is called a modified letter.

• In some languages, a modified letter (with a diacritic) is considered as a simple variant of the basic letter (without diacritic). For instance, in Portuguese, ç is nothing but a variant of the letter c.
• In other languages, a modified letter may be considered as an independent letter, having its own place in the alphabet and being totally distinct from the diacritic-less letter. For instance, in Turkish, ç is a different letter from c.

Quantity and frequency

The quantitity and the frequency of diacritics may differ.

• Some languages have no diacritics at all in the current use. It is notably the case of English and Malay (although some diacritics may be seen in some borrowings, as in English café or cafe, a word of French origin).

• A lot of languages use diacritics, which frequency varies a lot according to the language in question. For instance, diacritics are quite rare in Dutch, which uses only ë, and in Italian, which uses mainly à, è, é, ì, ò, ù. On the opposite, other languages use a lot of different diacritics, sometimes placed on nearly each sentence or on nearly each word, as in Vietnamese or in classical Greek.

Mandatory or optional uses

Diacritics may be mandatory or optional, depending on the language in question.

Pedagogical use

Some languages use certain diacritics only as a pedagogical help and remove them in general use. For instance, Russian only uses the acute accent (´) in learner-oriented publications, in order to show the place of the stress.

Diacritics on uppercases

In the writing systems which distinguish uppercase and lowercase letters, a few languages tend to supress or displace certain diacritics on uppercase letters, under certain circumstances.

• When uppercases and lowercases are mixed:
  • In Greek, a diacritic is above a lowercase but goes on the upper left side of an initial uppercase: ύφαλος (ýfalos, “underwater reef”) becomes Ύφαλος.
  • Some users of French remove diacritics on initial uppercases, but this is nonstandard: école (“school”) becomes École or less correctly Ecole.
• In all-uppercase writings:
  • In Greek, all diacritics except the dieresis are removed in all-uppercase writings: νερό (neró, “water”) becomes ΝΕΡΟ.
  • In Spanish and French, some users remove all diacritics in all-uppercase writings, but this is nonstandard: Spanish águila (“eagle”) becomes ÁGUILA or less correctly AGUILA, French côté (“side”) becomes CÔTÉ or less correctly COTE.
  • In Italian, the only usual diacritics are an acute accent and sometimes a grave accent on a final letter. This accent may be replaced by an apostrophe on the upper right side of the last letter, especially in all-uppercase writings, but this is nonstandard: libertà (“freedom”) becomes LIBERTÀ or less correctly LIBERTA’.

Number of affected characters

In general, a diacritic affects one character.

In a few languages, however, a diacritic is used to modify a group of letters, for instance in Maltese (għ, GĦ), in Breton (c’h), in Manx (çh), in Catalan (l·l), in Occitan (n·h, s·h) or in Francoprovençal (ch·).