Chapter 1: Introduction.- PART ONE.- Chapter 2: Language and multilingualism.- Chapter 3: Use of languages across the curriculum.- Chapter 4: Opportunities to learn (through) languages.- PART TWO.- Chapter 5: Primary schools with heritage language students.- Chapter 6: A whole-school primary bilingual program.- Chapter 7: Teacher-driven CLIL initiatives in secondary schools.- Chapter 8: A structured opt-in secondary CLIL program.- PART THREE.- Chapter 9: Teaching and learning objectives.- Chapter 10: Multilingual practices and opportunities to learn.- Chapter 11: Conclusion.