Diacritics are orthographical marks added above or below a letter (or sometimes within or between letters). In the Latin alphabet, they are basically used to indicate a modification in the pronunciation of the letter in question.
Although languages make use of a large number of such marks, in our context the most common diacritics are the so-called grave (`) or acute (´) accents, the cedilla (¸), the umlaut/dierisis (¨), the tilde (~) and the circumflex (^).
Unlike other European languages, modern English does not have diacritics. Some borrowed words may be written in English with their original non-English diacritic, but this rarely affects pronunciation (for exceptional cases, see the subsection Diacritics and their effect on pronunciation, below).
However, even with words borrowed fairly recently from languages that do make use of such orthographic marks, there is actually no obligation in English to use the original diacritic. An example of this is façade, borrowed from French, which can also be correctly written as facade (the pronunciation is identical for both forms: /fə’sa:d/), though some users feel uncomfortable if the cedilla is omitted. For such cases, consult a reliable English dictionary.
- Diacritics and their effect on pronunciationUse diacritics when their absence could result in incorrect pronunciation.
The form Barca (referring to the football team) might lead readers to pronounce the word /’ba:kə /, which would be incorrect, and so in this case the cedilla assists in pointing readers to the accepted pronunciation.
- Diacritics in foreign proper nounsUse diacritics in all proper nouns (i.e., names) in foreign languages, for reasons of textual tradition.
- Diacritics in foreign words that are not proper nounsWhen an English text uses foreign words or phrases that are not proper nouns but that have a diacritic in the original language, you should either keep all such marks or else use none at all. Be consistent. If you decide to use them, remember that they should also be used on capital letters and in headings.