Portal:Linguistics/Featured article/July 2008
An isogloss is the geographical boundary of a certain linguistic feature, e.g. the pronunciation of a vowel, the meaning of a word, or use of some syntactic feature. Major dialects are typically demarcated by whole bundles of isoglosses, e.g. the Benrath line that distinguishes High German from the other West Germanic languages; or the La Spezia-Rimini Line which divides the eastern Romance languages from the western ones. Undoubtedly, the largest well-known isogloss is the Centum-Satem isogloss, which traditionally separates the Indo-European languages into two distinct categories.