“…Some of them have focused on students' grammar concepts, drawing on verbal data such as questionnaires, interviews, and classroom logs (König, 1992;Mesch & Dammert, 2015;Müller & Tophinke, 2015;Peyer, 1997;Riehme, 1972;Rose, 1997;Schübel, 2000;Schuttkowski, Rothstein, Schmitz & Gräsel, 2015;Spies, 1989). Other studies drew on test data to investigate students' grammar knowledge (Claus-Schulze, 1966;Funke, 2005;Habermann, 2013).…”