The research reported here represents a qualitative case study that engaged teachers as participants over a prolonged period, examining their teaching practices and agentive roles in the language development of their students. This study draws on a social constructivist framework and transformative learning theory, both of which approach the learner as an agentive self and in the socio-cultural context of language learning. Data collection took place at an all-female university in the Kingdom of Saudi Arabia (KSA). It includes face-to-face semi-structured interviews of six teachers from two different classrooms, classroom observations (of two of the six teachers), and audio recordings of instructional practices. The findings reveal that the implementation of autonomous learning is a significant factor in students' intrinsic engagement and motivation to develop vocabulary knowledge. This study aims to offer guidance to language teachers and researchers who advocate for learner autonomy and innovative classroom practices. It recommends new strategies for cultivating learner autonomy in English education, both in the KSA classroom and elsewhere.