This qualitative study explores teachers' perspectives on learner motivation for English in Chilean secondary schools. Drawing both on motivation theories and on concepts related to teacher cognition, autonomy and agency, the analysis of 19 semi-structured interviews with Chilean English teachers sheds light on the difficulties that many teachers have in motivating their students so that they engage in classroom activities and learning. Findings show that teachers with a developed sense of agency report higher levels of learner motivation. Salient features of their accounts are classroom practices that grant students immediate positive experiences while learning English, rather than referring to future benefits. Other features are autonomous learning tasks, and a context-appropriate, empowering selection of cultural contents. The discussion suggests that teachers need to develop a sound sense of agency to identify "spaces to manoeuvre" between external constraints, such as curricular policies or lack of parental support, and possible internal constraints, such as paralysing beliefs about their own competence or a limited cultural repertoire to draw on in order to make English lessons motivating and meaningful for their students. For improved learner motivation and meaningful learning, research needs to support teachers' autonomy in times of increasing curricular regulation and standardisation of knowledge.