diacritiques

Diacritics, also called diacritical marks or diacritiques, are signs added to letters to alter their pronunciation, stress, or meaning. They occur in many writing systems and can be essential for distinguishing otherwise identical words or sounds.

Common categories include accent marks used on vowels, such as the acute (á), grave (à), and circumflex (â); the tilde (ñ, ã) often indicating nasalization or vowel quality; diaeresis or umlaut (ä, ö) to indicate a separate vowel sound; the cedilla (ç); and the caron or hacek (č, š). Other marks include the ogonek (ą, ę), the ring above (å), and length or quality marks such as the macron (ā) and breve (ă). Diacritics can also modify consonants or denote special phonetic values, as with the dot above or below, or the horn. Across languages, diacritics fulfill phonological, orthographic, or semantic roles, helping to distinguish words and sounds that would otherwise be indistinguishable.

In usage, diacritics reflect pronunciation, tone, or historical spelling. French uses accents to indicate pronunciation and differentiate homographs; Spanish uses the tilde on the letter n to form ñ; Romanian and Czech rely on numerous diacritics to represent distinct phonemes; Vietnamese employs a complex system of diacritics to mark both vowel quality and tone. In computing, diacritics may be represented as precomposed characters (é) or as base letters plus combining marks, a distinction that matters for text encoding, normalization, searching, and rendering. Diacritics also feature in transliteration and phonetic transcription, such as pinyin tones (mā, má) and IPA markings.