Diacritic


A diacritic is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek, from διακρίνω. The word diacritic is a noun, though it is sometimes used in an attributive sense, whereas diacritical is only an adjective. Some diacritics, such as the acute, grave, and circumflex, are often called accents. Diacritics 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 diacritics in Latin script is to change the sound-values of the letters to which they are added. Historically, English has used the diaeresis diacritic to indicate the correct pronunciation of ambiguous words, such as "coöperate", without which the letter sequence could be misinterpreted to be pronounced. Other examples are the acute and grave accents, which can indicate that a vowel is to be pronounced differently than is normal in that position, for example not reduced to /ə/ or silent as in the case of the two uses of the letter e in the noun résumé and the help sometimes provided in the pronunciation of some words such as doggèd, learnèd, blessèd, and especially words pronounced differently than normal in poetry.
Most other words with diacritics in English are borrowings from languages such as French to better preserve the spelling, such as the diaeresis on naïve and Noël, the acute from café, the circumflex in the word crêpe, and the cedille in façade. All these diacritics, however, are frequently omitted in writing, and English is the only major modern European language that does not have diacritics in common usage.
In Latin-script alphabets in other languages diacritics may distinguish between homonyms, such as the French là versus la, which are both pronounced. In Gaelic type, a dot over a consonant indicates lenition of the consonant in question. In other writing systems, diacritics may perform other functions. Vowel pointing systems, namely the Arabic harakat and the Hebrew niqqud systems, indicate vowels that are not conveyed by the basic alphabet. The Indic virama and the Arabic sukūn mark the absence of vowels. Cantillation marks indicate prosody. Other uses include the Early Cyrillic titlo stroke and the Hebrew gershayim, which, respectively, mark abbreviations or acronyms, and Greek diacritical marks, which showed that letters of the alphabet were being used as numerals. In Vietnamese and the Hanyu Pinyin official romanization system for Mandarin in China, diacritics are used to mark the tones of the syllables in which the marked vowels occur.
In orthography and collation, a letter modified by a diacritic may be treated either as a new, distinct letter or as a letter–diacritic combination. This varies from language to language and may vary from case to case within a language.
In some cases, letters are used as "in-line diacritics", with the same function as ancillary glyphs, in that they modify the sound of the letter preceding them, as in the case of the "h" in the English pronunciation of "sh" and "th". Such letter combinations are sometimes even collated as a single distinct letter. For example, the spelling sch was traditionally often treated as a separate letter in German. Words with that spelling were listed after all other words spelled with s in card catalogs in the Vienna public libraries, for example.

Types

Among the types of diacritic used in alphabets based on the Latin script are:
The tilde, dot, comma, titlo, apostrophe, bar, and colon are sometimes diacritical marks, but also have other uses.
Not all diacritics occur adjacent to the letter they modify. In the Wali language of Ghana, for example, an apostrophe indicates a change of vowel quality, but occurs at the beginning of the word, as in the dialects ’Bulengee and ’Dolimi. Because of vowel harmony, all vowels in a word are affected, so the scope of the diacritic is the entire word. In abugida scripts, like those used to write Hindi and Thai, diacritics indicate vowels, and may occur above, below, before, after, or around the consonant letter they modify.
The tittle on the letter or the letter, of the Latin alphabet originated as a diacritic to clearly distinguish from the minims of adjacent letters. It first appeared in the 11th century in the sequence ii, then spread to i adjacent to m, n, u, and finally to all lowercase is. The, originally a variant of i, inherited the tittle. The shape of the diacritic developed from initially resembling today's acute accent to a long flourish by the 15th century. With the advent of Roman type it was reduced to the round dot we have today.
Several languages of eastern Europe use diacritics on both consonants and vowels, whereas in western Europe digraphs are more often used to change consonant sounds. Most languages in Europe use diacritics on vowels, aside from English where there are typically none.

Diacritics specific to non-Latin alphabets

Arabic

  • hamza: indicates a glottal stop.
  • tanwīn symbols: Serve a grammatical role in Arabic. The sign ـً is most commonly written in combination with alif, e.g. ـًا.
  • shadda: Gemination of consonants.
  • waṣla: Comes most commonly at the beginning of a word. Indicates a type of hamza that is pronounced only when the letter is read at the beginning of the talk.
  • madda: A written replacement for a hamza that is followed by an alif, i.e.. Read as a glottal stop followed by a long, e.g. ءاداب، ءاية، قرءان، مرءاة are written out respectively as آداب، آية، قرآن، مرآة. This writing rule does not apply when the alif that follows a hamza is not a part of the stem of the word, e.g. نتوءات is not written out as نتوآت as the stem نتوء does not have an alif that follows its hamza.superscript alif :
  • * fatḥa
  • * kasra
  • * ḍamma
  • * sukūn
  • The ḥarakāt or vowel points serve two purposes:
  • * They serve as a phonetic guide. They indicate the presence of short vowels or their absence.
  • * At the last letter of a word, the vowel point reflects the inflection case or conjugation mood.
  • ** For nouns, The ḍamma is for the nominative, fatḥa for the accusative, and kasra for the genitive.
  • ** For verbs, the ḍamma is for the imperfective, fatḥa for the perfective, and the sukūn is for verbs in the imperative or jussive moods.
  • Vowel points or tashkīl should not be confused with consonant points or Arabic diacritics – one, two or three dots written above or below a consonant to distinguish between letters of the same or similar form.

Greek

These diacritics are used in addition to the acute, grave, and circumflex accents and the diaeresis: – iota subscript – rough breathing : aspiration – smooth (or soft) breathing : lack of aspiration

Hebrew

Korean

The diacritics 〮 and 〯, known as Bangjeom, were used to mark pitch accents in Hangul for Middle Korean. They were written to the left of a syllable in vertical writing and above a syllable in horizontal writing.

Syriac

  • A dot above and a dot below a letter represent, transliterated as a or ă,
  • Two diagonally-placed dots above a letter represent, transliterated as ā or â or å,
  • Two horizontally-placed dots below a letter represent, transliterated as e or ĕ; often pronounced and transliterated as i in the East Syriac dialect,
  • Two diagonally-placed dots below a letter represent, transliterated as ē,
  • A dot underneath the Beth represent a soft sound, transliterated as v
  • A tilde placed under Gamel represent a sound, transliterated as j
  • The letter Waw with a dot below it represents, transliterated as ū or u,
  • The letter Waw with a dot above it represents, transliterated as ō or o,
  • The letter Yōḏ with a dot beneath it represents, transliterated as ī or i,
  • A tilde under Kaph represent a sound, transliterated as ch or č,
  • A semicircle under Peh represents an sound, transliterated as f or ph.
In addition to the above vowel marks, transliteration of Syriac sometimes includes ə, e̊ or superscript e to represent an original Aramaic schwa that became lost later on at some point in the development of Syriac. Some transliteration schemes find its inclusion necessary for showing spirantization or for historical reasons.

Non-alphabetic scripts

Some non-alphabetic scripts also employ symbols that function essentially as diacritics.
  • Non-pure abjads and abugidas use diacritics for denoting vowels. Hebrew and Arabic also indicate consonant doubling and change with diacritics; Hebrew and Devanagari use them for foreign sounds. Devanagari and related abugidas also use a diacritical mark called a virama to mark the absence of a vowel. In addition, Devanagari uses the moon-dot chandrabindu for vowel nasalization.
  • Unified Canadian Aboriginal Syllabics use several types of diacritics, including the diacritics with alphabetic properties known as Medials and Finals. Although long vowels originally were indicated with a negative line through the Syllabic glyphs, making the glyph appear broken, in the modern forms, a dot above is used to indicate vowel length. In some of the styles, a ring above indicates a long vowel with a off-glide. Another diacritic, the "inner ring" is placed at the glyph's head to modify to and to . Medials such as the "w-dot" placed next to the Syllabics glyph indicates a being placed between the syllable onset consonant and the nucleus vowel. Finals indicate the syllable coda consonant; some of the syllable coda consonants in word medial positions, such as with the "h-tick", indicate the fortification of the consonant in the syllable following it.
  • The Japanese hiragana and katakana syllabaries use the dakuten (◌゛) and handakuten (◌゜) symbols, also known as nigori or ten-ten and maru, to indicate voiced consonants or other phonetic changes.
  • Emoticons are commonly created with diacritic symbols, especially Japanese emoticons on popular imageboards.

Alphabetization or collation

Different languages use different rules to put diacritic characters in alphabetical order. For example, French and Portuguese treat letters with diacritical marks the same as the underlying letter for purposes of ordering and dictionaries. The Scandinavian languages and the Finnish language, by contrast, treat the characters with diacritics,, and as distinct letters of the alphabet, and sort them after. Usually and are sorted as equivalent to and . Also, aa, when used as an alternative spelling to, is sorted as such. Other letters modified by diacritics are treated as variants of the underlying letter, with the exception that is frequently sorted as.
Languages that treat accented letters as variants of the underlying letter usually alphabetize words with such symbols immediately after similar unmarked words. For instance, in German where two words differ only by an umlaut, the word without it is sorted first in German dictionaries. However, when names are concerned, umlauts are often treated as combinations of the vowel with a suffixed ; Austrian phone books now treat characters with umlauts as separate letters.
In Spanish, the grapheme is considered a distinct letter, different from and collated between and, as it denotes a different sound from that of a plain. But the accented vowels,,,, are not separated from the unaccented vowels,,,,, as the acute accent in Spanish only modifies stress within the word or denotes a distinction between homonyms, and does not modify the sound of a letter.
For a comprehensive list of the collating orders in various languages, see Collating sequence.

Generation with computers

Modern computer technology was developed mostly in countries that speak Western European languages, and many early binary encodings were developed with a bias favoring Englisha language written without diacritical marks. With computer memory and computer storage at premium, early character sets were limited to the Latin alphabet, the ten digits and a few punctuation marks and conventional symbols. The American Standard Code for Information Interchange, first published in 1963, encoded just 95 printable characters. It included just four free-standing diacriticsacute, grave, circumflex and tildewhich were to be used by backspacing and overprinting the base letter. The ISO/IEC 646 standard defined national variations that replace some American graphemes with precomposed characters, according to languagebut remained limited to 95 printable characters.
Unicode was conceived to solve this problem by assigning every known character its own code; if this code is known, most modern computer systems provide a method to input it. For historical reasons, almost all the letter-with-accent combinations used in European languages were given unique code points and these are called precomposed characters. For other languages, it is usually necessary to use a combining character diacritic together with the desired base letter. Unfortunately, even as of 2024, many applications and web browsers remain unable to operate the combining diacritic concept properly.
Depending on the keyboard layout and keyboard mapping, it is more or less easy to enter letters with diacritics on computers and typewriters. Keyboards used in countries where letters with diacritics are the norm, have keys engraved with the relevant symbols. In other cases, such as when the US international or UK extended mappings are used, the accented letter is created by first pressing the key with the diacritic mark, followed by the letter to place it on. This method is known as the dead key technique, as it produces no output of its own but modifies the output of the key pressed after it.

Languages with letters containing diacritics

The following languages have letters with diacritics that are orthographically distinct from those without diacritics.

Diacritics that do not produce new letters

English

English is one of the few European languages that does not have many words that contain diacritical marks. Instead, digraphs are the main way the Modern English alphabet adapts the Latin to its phonemes. Exceptions are unassimilated foreign loanwords, including borrowings from French ; however, the diacritic is also sometimes omitted from such words. Loanwords that frequently appear with the diacritic in English include café, résumé or resumé, soufflé, and naïveté. In older practice, one may see examples such as élite, mêlée and rôle.
English speakers and writers once used the diaeresis more often than now in words such as coöperation, zoölogy, and seeër as a way of indicating that adjacent vowels belonged to separate syllables, but this practice has become far less common. The New Yorker magazine is a major publication that continues to use the diaeresis in place of a hyphen for clarity and economy of space.
A few English words, often when used out of context, especially in isolation, can only be distinguished from other words of the same spelling by using a diacritic or modified letter. These include exposé, lamé, maté, öre, øre, résumé and rosé. In a few words, diacritics that did not exist in the original have been added for disambiguation, as in maté '', saké , and Malé ,'' to clearly distinguish them from the English words mate, sake, and male.
The acute and grave accents are occasionally used in poetry and lyrics: the acute to indicate stress overtly where it might be ambiguous or nonstandard for metrical reasons, the grave to indicate that an ordinarily silent or elided syllable is pronounced.
In certain personal names such as Renée and Zoë, often two spellings exist, and the person's own preference will be known only to those close to them. Even when the name of a person is spelled with a diacritic, like Charlotte Brontë, this may be dropped in English-language articles, and even in official documents such as passports, due either to carelessness, the typist not knowing how to enter letters with diacritical marks, or technical reasons. They also appear in some worldwide company names and/or trademarks, such as Nestlé and Citroën.

Other languages

The following languages have letter-diacritic combinations that are not considered independent letters.
  • Afrikaans uses a diaeresis to mark vowels that are pronounced separately and not as one would expect where they occur together, for example voel as opposed to voël. The circumflex is used in ê, î, ô and û generally to indicate long close-mid, as opposed to open-mid vowels, for example in the words wêreld and môre. The acute accent is used to add emphasis in the same way as underlining or writing in bold or italics in English, for example Dit is jóú boek. The grave accent is used to distinguish between words that are different only in placement of the stress, for example appel and appèl and in a few cases where it makes no difference to the pronunciation but distinguishes between homophones. The two most usual cases of the latter are in the sayings òf... òf and nòg... nòg to distinguish them from of and nog.
  • Aymara uses a diacritical horn over p, q, t, k, ch.
  • Catalan has the following composite characters: à, ç, é, è, í, ï, ó, ò, ú, ü, l·l. The acute and the grave indicate stress and vowel height, the cedilla marks the result of a historical palatalization, the diaeresis indicates either a hiatus, or that the letter u is pronounced when the graphemes gü, qü are followed by e or i, the interpunct distinguishes the different values of ll/l·l.
  • Some orthographies of Cornish such as Kernowek Standard and Unified Cornish use diacritics, while others such as Kernewek Kemmyn and the Standard Written Form do not.
  • Dutch uses the diaeresis. For example, in ruïne it means that the u and the i are separately pronounced in their usual way, and not in the way that the combination ui is normally pronounced. Thus it works as a separation sign and not as an indication for an alternative version of the i. Diacritics can be used for emphasis or for disambiguation between a number of words that are spelled the same when context does not indicate the correct meaning. Grave and acute accents are used on a very small number of words, mostly loanwords. The ç also appears in some loanwords.
  • Faroese. Non-Faroese accented letters are not added to the Faroese alphabet. These include é, ö, ü, å and recently also letters like š, ł, and ć.
  • Filipino has the following composite characters: á, à, â, é, è, ê, í, ì, î, ó, ò, ô, ú, ù, û. Everyday use of diacritics for Filipino is, however, uncommon, and meant only to distinguish between homonyms between a word with the usual penultimate stress and one with a different stress placement. This aids both comprehension and pronunciation if both are relatively adjacent in a text, or if a word is itself ambiguous in meaning. The letter ñ is not a n with a diacritic, but rather collated as a separate letter, one of eight borrowed from Spanish. Diacritics appear in Spanish loanwords and names observing Spanish orthography rules.
  • Finnish. Carons in š and ž appear only in foreign proper names and loanwords, but may be substituted with sh or zh if and only if it is technically impossible to produce accented letters in the medium. Contrary to Estonian, š and ž are not considered distinct letters in Finnish.
  • French uses five diacritics. The grave marks the sound when over an e, as in père or is used to distinguish words that are otherwise homographs such as a/''à or ou/où. The acute is only used in "é", modifying the "e" to make the sound, as in étoile. The circumflex generally denotes that an "s" once followed the vowel in Old French or Latin, as in fête, the Old French being feste and the Latin being festum. Whether the circumflex modifies the vowel's pronunciation depends on the dialect and the vowel. The cedilla indicates that a normally hard "c" is to be pronounced, as in ça. The diaeresis diacritic indicates that two adjacent vowels that would normally be pronounced as one are to be pronounced separately, as in Noël.
  • Galician vowels can bear an acute to indicate stress or difference between two otherwise same written words, but the diaeresis is only used with ï'' and ü to show two separate vowel sounds in pronunciation. Only in foreign words may Galician use other diacritics such as ç, ê, or à.
  • German uses the three umlauted characters ä, ö and ü. These diacritics indicate vowel changes. For instance, the word Ofen "oven" has the plural Öfen. The mark originated as a superscript e; a handwritten blackletter e resembles two parallel vertical lines, like a diaeresis. Due to this history, "ä", "ö" and "ü" can be written as "ae", "oe" and "ue" respectively, if the umlaut letters are not available.
  • Hebrew has many various diacritic marks known as niqqud that are used above and below script to represent vowels. These must be distinguished from cantillation, which are keys to pronunciation and syntax.
  • The International Phonetic Alphabet uses diacritic symbols and characters to indicate phonetic features or secondary articulations.
  • Irish uses the acute to indicate that a vowel is long: á, é, í, ó, ú. It is known as síneadh fada "long sign" or simply fada "long" in Irish. In the older Gaelic type, overdots are used to indicate lenition of a consonant: ḃ, ċ, ḋ, ḟ, ġ, ṁ, ṗ, ṡ, ṫ.
  • Italian mainly has the acute and the grave, typically to indicate a stressed syllable that would not be stressed under the normal rules of pronunciation but sometimes also to distinguish between words that are otherwise spelled the same way. Despite its rare use, Italian orthography allows the circumflex too, in two cases: it can be found in old literary context to signal a syncope, or in modern Italian to signal the contraction of ″-ii″ due to the plural ending -i whereas the root ends with another -i; e.g., s. demonio, p. demonii→demonî; in this case the circumflex also signals that the word intended is not demoni, plural of "demone" by shifting the accent.
  • Lithuanian uses the acute, grave and tilde in dictionaries to indicate stress types in the language's pitch accent system.
  • Maltese also uses the grave on its vowels to indicate stress at the end of a word with two syllables or more:– lowercase letters: à, è, ì, ò, ù; capital letters: À, È, Ì, Ò, Ù
  • Māori makes use of macrons to mark long vowels.
  • Occitan has the following composite characters: á, à, ç, é, è, í, ï, ó, ò, ú, ü, n·h, s·h. The acute and the grave indicate stress and vowel height, the cedilla marks the result of a historical palatalization, the diaeresis indicates either a hiatus, or that the letter u is pronounced when the graphemes gü, qü are followed by e or i, and the interpunct distinguishes the different values of nh/n·h and sh/s·h.
  • Portuguese has the following composite characters: à, á, â, ã, ç, é, ê, í, ó, ô, õ, ú. The acute and the circumflex indicate stress and vowel height, the grave indicates crasis, the tilde represents nasalization, and the cedilla marks the result of a historical lenition.
  • Acutes are also used in Slavic language dictionaries and textbooks to indicate lexical stress, placed over the vowel of the stressed syllable. This can also serve to disambiguate meaning means "to write", but пи́сать, or "бо́льшая часть" vs "больша́я часть".
  • Spanish uses the acute and the diaeresis. The acute is used on a vowel in a stressed syllable in words with irregular stress patterns. It can also be used to "break up" a diphthong as in tío. Moreover, the acute can be used to distinguish words that otherwise are spelled alike, such as si and sí, and also to distinguish interrogative and exclamatory pronouns from homophones with a different grammatical function, such as donde/¿dónde? or como/¿cómo?. The acute may also be used to avoid typographical ambiguity, as in 1 ó 2 for it to be pronounced in the combinations gue and gui, where u is normally silent, for example ambigüedad. In poetry, the diaeresis may be used on i and u as a way to force a hiatus. As foreshadowed above, in nasal ñ the tilde is not considered a diacritic sign at all, but a composite part of a distinct glyph, with its own chapter in the dictionary: a glyph that denotes the 15th letter of the Spanish alphabet.
  • Swedish uses the acute to show non-standard stress, for example in kafé and resumé. This occasionally helps resolve ambiguities, such as ide versus idé. In these words, the acute is not optional. Some proper names use non-standard diacritics, such as Carolina Klüft and Staël von Holstein. For foreign loanwords the original accents are strongly recommended, unless the word has been infused into the language, in which case they are optional. Hence crème fraîche but ampere. Swedish also has the letters å, ä, and ö, but these are considered distinct letters, not a and o with diacritics.
  • Tamil does not have any diacritics in itself, but uses the Arabic numerals 2, 3 and 4 as diacritics to represent aspirated, voiced, and voiced-aspirated consonants when Tamil script is used to write long passages in Sanskrit.
  • Thai has its own system of diacritics derived from Indian numerals, which denote different tones.
  • Vietnamese uses the acute, the grave, the tilde, the underdot and the hook above on vowels as tone indicators.
  • Welsh uses the circumflex, diaeresis, acute, and grave on its seven vowels a, e, i, o, u, w, y. The most common is the circumflex to denote a long vowel, usually to disambiguate it from a similar word with a short vowel or a semivowel. The rarer grave accent has the opposite effect, shortening vowel sounds that would usually be pronounced long. The acute accent and diaeresis are also occasionally used, to denote stress and vowel separation respectively. The w-circumflex and the y-circumflex are among the most commonly accented characters in Welsh, but unusual in languages generally, and were until recently very hard to obtain in word-processed and HTML documents.

Transliteration

Several languages that are not written with the Roman alphabet are transliterated, or romanized, using diacritics. Examples:

Limits

Orthographic

Possibly the greatest number of combining diacritics required to compose a valid character in any Unicode language is 8, for the "well-known grapheme cluster in Tibetan and Ranjana scripts" or HAKṢHMALAWARAYAṀ.
It consists of
An example of the rendering, which may be broken depending on the browser used:

Unorthographic/ornamental

Some users have explored the limits of rendering in web browsers and other software by "decorating" words with excessive nonsensical diacritics per character to produce so-called Zalgo text.

List of diacritics in Unicode

Diacritics for Latin script in Unicode:
CharacterCharacter name
MarkGeneral categoryScript