Passage: Pompeu Fabra i Poch (Catalan pronunciation: [pumˈpɛw ˈfaβɾə]; Gràcia, Barcelona, 20 February 1868 - Prada de Conflent, 25 December 1948) was a Catalan engineer and grammarian. He was the main author of the normative reform of contemporary Catalan language.

Question: Aside from his engineering career, Pompeu Fabra i Poch was also well known in what other area of expertise?
grammarian