Karl Brugmann originally intended to include a volume on syntax in his comparative grammar of Indo-European, but as that ambitious project expanded, he and his publisher enlisted Berthold Delbrück (1842–1922) to take on the treatment of syntax. Delbrück's three volumes on inflection and phrase and sentence structure appeared between 1893 and 1900 and remain the fullest treatment of Indo-European syntax to this day. His second volume, published in 1897, is devoted to the verb. Delbrück, while referring to work by other linguists, largely relies on his own research. He pays particular attention to Greek and Sanskrit, but also discusses other sub-families including Germanic, Italic and Slavic. The volume provides thorough coverage of tense, mood, infinitives and participles.