A practical guide to teaching inclusive, engaging and challenging English that is truly cognitively based, deriving from robust research that led to the Cognitive Acceleration through Science Education (CASE) programme. Let's Think in English is both an introduction and an invitation: a guide for teachers who believe that the true purpose of English is not simply to analyse texts, but to develop young people's capacity to think. Grounded in the principles of Cognitive Acceleration, first developed at King's College London, Let's Think in English (LTE) offers a carefully designed programme of lessons that challenge learners to engage more deeply, reason more clearly and think more systematically. Now used in hundreds of schools across the UK and internationally, LTE has gained a reputation for transforming not only students' thinking, but also the quality of classroom experience itself. This book provides a clear pathway into becoming an LTE teacher. Blending research, theory and rich classroom case studies, it explores how and why structured cognitive challenge can lead to lasting intellectual growth. At its core is a powerful belief: that intelligence is not fixed, but can be developed through carefully mediated learning, dialogue and productive struggle. Central to LTE is the idea that thinking must be made visible through talk. Classrooms become spaces of genuine dialogue-- where ideas are explored rather than asserted, where uncertainty is welcomed, and where learners collaboratively build more complex understandings. In this environment, students not only deepen their comprehension of texts but also develop confidence, resilience and a stronger sense of belonging. At a time when attention is increasingly fragmented and technology can shortcut the thinking process, LTE offers a vital counterbalance. It slows learning down, encourages reflection and places value on the process of thinking itself. Structured to support both new and experienced practitioners, the book guides readers from theory to practice and beyond. Ultimately, it is a compelling case for reimagining English classrooms as communities of inquiry-- where thinking deeply, together, becomes both the means and the reward of learning.