Language teacher cognition has been an area of research interest for more than three decades, diversifying in recent years into a wide range of academic areas such as teacher development, initial teacher education, grammar teaching, literacy instruction, task-based learning, phonology, testing, technology, and classroom research. Much of this research, however, has been based in private language institutes or universities in developed countries, especially English-speaking ones, and has focused on identifying and describing individual teacher cognitions mostly in novice native-speaker practitioners. The present study aims to help redress this tendency by examining the cognitions and experiences, and the relationships among them, of two experienced non-native speaker teachers of English working at a state secondary school in Argentina. Using multi-methods such as semi-structured interviews, autobiographical accounts, classroom observation, stimulated recall, teacher diaries, and a grammaticality judgement task, this research project explores the teachers’ prior language learning experiences, knowledge about grammar, and grammar-related pedagogical knowledge in relation to their actual grammar teaching practices. In addition, there is a focus on the role which contextual factors play in shaping the application of these experiential and cognitive constructs, and on the interplay among these factors to help define the teachers’ grammar pedagogical decisions and actions. The findings reveal that experiential and cognitive factors appear to account for the major differences between these teachers’ teaching theories, practices, and rationales; whereas context-bound influences explain the similarities between their classroom instructional actions. They also show that language teacher cognition is informed by different sources (the teachers’ personal and prior educational history, their professional education, and their accumulated experience) and that teachers construct a context, instantiated by the interaction between their language teacher cognition and the contextual factors inside and around the classroom, which mediates between their cognitions and practice. These results carry direct implications for those involved in teacher cognition, language teacher research, teacher education, and materials design.