Chapter 1. Introduction to the Issue: New Insights into CLIL Characterization, Implementation, and Training.- Chapter 2. Characterizing Representative CLIL Practices: An Andalusian Case Study.- Chapter 3. Stakeholder Perspectives on CLIL Implementation: Evidence from a Large-scale Program Evaluation.- Chapter 4. Investigating the Effects of CLIL on Language Attainment: Instrument Design and Validation.- Chapter 5. The Effects of CLIL on L1 Competence Development.- Chapter 6. The Impact of CLIL on L2 Grammar and Vocabulary.- Chapter 7. The Impact of CLIL on L2 Oral Comprehension and Production: A Longitudinal Study.- Chapter 8. The Effects of CLIL on L2 Written Comprehension and Production.- Chapter 9. The Effects of CLIL on Subject Matter Learning: The Case of Science in Primary and Secondary Education.- Chapter 10. Teacher Training for CLIL: Are We there Yet?.- Chapter 11. Final Commentary: Future Challenges and Ways Forward for CLIL Characterization, Implementation, and Training.