umlauts

An umlaut is a diacritic mark consisting of two small dots placed over a vowel, most commonly seen in the German letters ä, ö, and ü. The term also refers to a historical sound change in which a vowel’s quality is altered by a following vowel, typically resulting in fronted or rounded vowels. In Germanic linguistics, umlaut describes this vowel mutation, and in orthography the two-dot mark indicates the written result of that change.

In German, umlauted vowels often appear in inflected or derived forms. Examples include Mann (man) becoming Männer (men), Haus (house) becoming Häuser (houses), and Maus (mouse) becoming Mäuse (mice). The umlaut is a productive part of the language’s morphology and phonology, though not every instance of ä, ö, or ü signals a historical umlaut in modern speech.

In other languages, two-dot diacritics are sometimes called a diaeresis or simply a diacritic, and are used to indicate that adjacent vowels are to be pronounced separately or belong to distinct morphemes. In English, the term umlaut is sometimes used informally for such marks (as in naïve or coöperate), but this usage is less about phonetic change and more about syllable separation in loanwords. Finnish and Swedish similarly use ä and ö as independent vowels, while other languages employ comparable diacritics with different functions.

Encoding and typography: the umlauted vowels are part of Unicode, for example Ä/ä (U+00C4/U+00E4), Ö/ö (U+00D6/U+00F6), and Ü/ü (U+00DC/U+00FC). The concept remains central to German orthography and to the study of Germanic phonology.