English rarely uses diacritics, which are symbols indicating the modification of a vowel's sound when spoken. Most of the affected words are in terms imported from other languages The two dots accent (diaeresis or umlaut), the grave accent and the acute accent are the only diacritics native to Modern English, and their usage has tended to fall off except in certain publications and particular cases. Proper nouns are not generally counted as English terms except when accepted into the language as an eponym – such as Geiger–Müller tube, or the English terms roentgen after Wilhelm Röntgen, and biro after László Bíró, in which case any diacritical mark is often lost. Unlike continental European languages, English orthography tends to use digraphs (like "sh", "oo", and "ea") rather than diacritics to indicate more sounds than can be accommodated by the letters of the Latin alphabet. Unlike other systems (such as Spanish orthography) where the spelling indicates the pronunciation, English spelling is highly varied, and diacritics alone would be insufficient to make it reliably phonetic. (See .) Types of diacritical marks Though limited, the following diacritical marks in English may be encountered, particularly for marking in poetry: the acute accent (née) and grave accent (English poetry marking, changèd), modifying vowels or marking stresses the circumflex (entrepôt), borrowed from French the diaeresis (Zoë), indicating a second syllable in two consecutive vowels the tittle, the dot found on the regular small i and small j, is removed when another diacritic is required the macron (English poetry marking, lēad pronounced , not ), lengthening vowels, as in Māori; or indicating omitted n or m (in pre-Modern English, both in print and in handwriting). the breve (English poetry marking, drŏll pronounced , not ), shortening vowels the umlaut (über), altering Germanic vowels the cedilla (soupçon), in French, Portuguese and in Catalan it is a softening c, indicating 's-' not 'k-' pronunciation the tilde (Señor, João), in Spanish indicating palatalised n, and Portuguese indicating nasal a and o (although in Spanish and most source languages, the tilde is not considered a diacritic over the letter n but rather as an integral part of the distinct letter ñ; in Portuguese the sound is represented by "nh") In representing European personal names, anthroponyms, and place names, toponyms, the following are often encountered: the háček (as in Karel Čapek), often also called the haček in English (adapted from "háček", the Czech