diacrieten

Diacrieten are marks added to letters to modify their pronunciation, stress, length, tone, or meaning. They occur in many languages and scripts and may be essential to a language’s orthography or used to distinguish otherwise identical words. Diacritics can be placed above, below, or through a letter, and may be single or multiple marks.

The most common diacritics include the acute (é, á), grave (è, à), and circumflex (â, ê), which signal vowel quality or reflect historical changes in spelling. The diaeresis or umlaut (ë, ï) indicates that adjacent vowels are pronounced separately in some languages, or a special vowel quality in others. The tilde (ñ, ã) marks nasalization or palatalization in several languages. The cedilla (ç) softens c to an s sound in French and other languages. The ring above (å) and the caron/hacek (č, š, ž) modify consonants or vowels. A dot above (i, j) or other diacritics color letters in various scripts. Macrons (ā) and breves (ă) indicate vowel length, where relevant.

In Dutch, diacritics are relatively uncommon but are used in specific cases to guide pronunciation or syllabification, notably the diaeresis (trema) to show that two vowels form separate syllables, as in reëel or coöperatie. In other languages, diacritics convey phonological or grammatical information, such as French accents or Vietnamese tone marks. In digital text, diacritics are encoded in Unicode, and their handling affects sorting, collation, and search.