Indo-European ablaut

Grammatical change of vowels in Indo-European languages In linguistics, the Indo-European ablaut (/ˈæb.laʊt/ AB-lowt, from German Ablaut pronounced [ˈap.laʊt]) is a system of apophony (regular vowel variations) in the Proto-Indo-European language (PIE). An example of ablaut in English is the strong verb sing, sang, sung and its related noun song, a paradigm inherited directly from the Proto-Indo-European stage of the language. Traces of ablaut are found in all modern Indo-European languages, though its prevalence varies greatly. History of the concept The linguistic phenomenon of ablaut was first recorded by Sanskrit grammarians in the later Vedic period (roughly 8th century BCE), and was codified by Pāṇini in his Aṣṭādhyāyī (4th century BCE), where the terms guṇa and vṛddhi were used to describe the phenomena now known respectively as the full grade and lengthened grade. In the context of European languages, the phenomenon was first described in the early 18th century by the Dutch linguist Lambert ten Kate, in his book Gemeenschap tussen de Gottische spraeke en de Nederduytsche ("Common aspects of the Gothic and Dutch languages", 1710). The term ablaut is borrow