ablaut
n.n. a pattern of vowel sounds in a word that shows how it changes to mean something different. It is a way to show the past tense or a different form of a verb.
n. a pattern of vowel alternation within a word or across a set of related words, used to indicate grammatical distinctions such as tense or aspect. Often refers to the internal vowel shift in Germanic languages.
The word 'sing' and 'sang' show a clear example of ablaut.
Linguists study ablaut to understand how ancient languages evolved and how different forms of a verb are connected.
In Proto-Indo-European, ablaut served as a primary means of inflection, allowing speakers to indicate the duration or intensity of an action through subtle shifts in the root vowel.
Borrowed from German Ablaut (“sound gradation”), which is from ab- or ab (“down, off”), + Laut (“sound”). Ab is used here in the sense of “deviating, varying” as in Abgott (“god other than the true God”), Abart (“different sort, variety, anomality”).