This study presents a new approach to tense-aspect teaching from the perspective of Cognitive Linguistics. Its aims are twofold: first, to provide a coherent account of the English tense-aspect system. To this end, a synthesis of Langacker's Cognitive Grammar theory and Fauconnier's Mental Space approach will be put forward. Second, to test the applicability and effectiveness of CL-informed learning materials in the language classroom. For that purpose, an empirical analysis was conducted involving German students of English at an upper-intermediate level. The study therefore addresses linguists and language teachers alike.