Frontmatter -- Contents -- Introduction -- Part 1: Theoretical Issues -- 1. Critical Period or General Age Factor(s)? -- 2. Phonological Acquisition in Multilingualism -- 3. Know Your Grammar: What the Knowledge of Syntax and Morphology in an L2 Reveals about the Critical Period for Second/foreign Language Acquisition -- Part 2: Fieldwork in Bilingual Communities -- 4. The Influence of Age on the Acquisition of English: General Proficiency, Attitudes and Code Mixing -- 5. Age, Length of Exposure and Grammaticality Judgements in the Acquisition of English as a Foreign Language -- 6. English FL Sounds in School Learners of Different Ages -- 7. Maturational Constraints on Foreign-language Written Production -- 8. Variation in Oral Skills Development and Age of Onset -- 9. Learner Strategies: A Cross-sectional and Longitudinal Study of Primary and High-school EFL Teachers