The paper examines the connection of language and urban form in the work of the German architect and urban planner Rudolf Schwarz. Schwarz, who is credited with having exerted major influence on the protagonists of modern architecture such as Mies van der Rohe, was one of the most famous architects in postwar Germany and the author of the 1950 plan for the rebuilding of Cologne's destroyed inner city. From the 1950s onwards, Cologne's once dense mediaeval nucleus was restructured by a network of six-lane thoroughfares and various sequences of scattered concrete blocks. This redesign, as radically modern as it may seem, was closely tied to Schwarz's traditionalist conception of language. His linguistic arguments were influenced by a century-long tradition among conservative German intellectuals, who strove for a deeper and unmediated understanding of the world through verbal communication. Claiming an intrinsic relationship between the structure of German grammar and of the phenomena it captures, they believed in the ‘rootedness’ of their nation in its geographic environment through language. In that respect, Schwarz's conception and use of language – which was in many ways exemplary for German city planners in the postwar era – laid the groundwork for the modernist transformation of the city and thus for a dilemma that haunted German urban planning in the decades that followed.