This article argues that grammatical thinking within a framework of phenomenological hermeneutics assists designing and may properly be used as a fundamental teaching approach for an interdisciplinary art and design studio. Furthermore, it argues that the theme of grammatical design awareness could be considered as a generic issue across all disciplines in the Arts and Humanities. It calls for a more explicit teaching of grammar, both in terms of understanding and application, and provides a case study to indicate how this might be achieved. It highlights the value of both schematic and formal systems when using notions of rules, grammar and contingency to assist and augment traditional pedagogical approaches used in design education. It recognizes the value of grammatical visual thinking and argues that an interdisciplinary "grammatical design studio" may provide a valuable foundation for the development of design thinking processes that offer transparency, consistency, creativity and reflectivity. (Contains 6 figures and 4 notes.)