diacrítico

Diacrítico (diacritic) is a mark added to a letter to alter its pronunciation or to distinguish meaning. Diacritics appear in many writing systems and are usually written above, below, or through the base letter. They can be combining marks added after the letter or precomposed characters that already include the mark.

The primary functions of diacritics are to indicate pronunciation, stress, tone, vowel quality or length, nasalization, or palatalization. They can also differentiate otherwise identical words. Their use is language-specific; some languages rely heavily on diacritics, while others use them sparingly.

Common types include the acute accent (é), grave accent (è), circumflex (ê), and tilde (ñ, ã); diaeresis or umlaut (ë, ï); the cedilla (ç); the caron or háček (č); the breve (ă); the dot above (ż); and the ring above (å). Each serves particular phonetic or orthographic purposes. For example, Spanish uses accents to mark stressed syllables and the tilde to form ñ; French uses several accents to indicate vowel quality and certain historical spellings; Portuguese employs tilde and nasal vowels; Vietnamese uses a system of diacritics for tone and vowel quality, resulting in many possible characters for a single base letter.

In computing, diacritics are encoded in Unicode as combining marks or as single precomposed characters. Text processing must handle normalization, case folding, and diacritic-insensitive searching and sorting. Diacritics also pose challenges for input methods and typography, especially in languages with extensive diacritic inventories.

The term diacrítico (diacritic) thus encompasses a broad set of signs essential to pronunciation, meaning, and orthography in many languages.