Grundriß der vergleichenden Grammatik der indogermanischen Sprachen (German for "Outline of the comparative grammar of the Indo-Germanic languages") is a major work of historical linguistics by Karl Brugmann and Berthold Delbrück, published in two editions between 1886 and 1916. Brugmann treated phonology and morphology, and Delbrück treated syntax. The grammar of Proto-Indo-European (PIE) is reconstructed from those of its daughter languages known in the late 19th century. The work represents a major step in Indo-European studies, after Franz Bopp's Comparative Grammar of 1833 and August Schleicher's Compendium of 1871. Brugmann's neogrammarian re-evaluation of PIE resulted in a view that in its essence continued to be valid until present times.