Germanic umlaut

The Germanic umlaut (sometimes called i-umlaut or i-mutation) is a type of linguistic umlaut in which a back vowel changes to the associated front vowel (fronting) or a front vowel becomes closer to /i/ (raising) when the following syllable contains /i/, /iː/, or /j/.

It took place separately in various Germanic languages starting around 450 or 500 CE and affected all of the early languages^[1] except Gothic.^[2] An example of the resulting vowel alternation is the English plural foot ~ feet (from Proto-Germanic *fōts, pl. *fōtiz). Germanic umlaut, as covered in this article, does not include other historical vowel phenomena that operated in the history of the Germanic languages such as Germanic a-mutation and the various language-specific processes of u-mutation, nor the earlier Indo-European ablaut (vowel gradation), which is observable in the conjugation of Germanic strong verbs such as sing/sang/sung.

While Germanic umlaut has had important consequences for all modern Germanic languages, its effects are particularly apparent in German, because vowels resulting from umlaut are generally spelled with a specific set of letters: ⟨ä⟩, ⟨ö⟩, and ⟨ü⟩, usually pronounced /ɛ/ (formerly /æ/), /ø/, and /y/. Umlaut is a form of assimilation or vowel harmony, the process by which one speech sound is altered to make it more like another adjacent sound. If a word has two vowels with one far back in the mouth and the other far forward, more effort is required to pronounce the word than if the vowels were closer together; therefore, one possible linguistic development is for these two vowels to be drawn closer together.