The Neogrammarians (German: Junggrammatiker, pronounced [ˈjʊŋɡʁaˌmatɪkɐ] ⓘ, lit.
'young grammarians') were a German school of linguists, originally at the University of Leipzig, in the late 19th century who proposed the Neogrammarian hypothesis of the regularity of sound change.
[1] According to the Neogrammarian hypothesis, a diachronic sound change affects simultaneously all words in which its environment is met, without exception.
Nonetheless, both of these challenges to exceptionlessness remain controversial, and many investigators continue to adhere to the Neogrammarian doctrine.
[a] Other contributions of the Neogrammarians to general linguistics were: Leading Neogrammarian linguists included: Despite their strong influence in their time, the methods and goals of the Neogrammarians have been criticized for reducing the object of investigation to the idiolect; restricting themselves to the description of surface phenomena (sound level); overvaluation of historical languages and neglect of contemporary ones.