Introduction1. Language learning in early childhoodPreviewFirst language acquisitionExplaining first language acquisitionLanguage disorders and delaysChildhood bilingualismSummarySuggestions for further reading2. Second language learningPreviewLearner characteristicsLearning conditionsStudying the language of second language learners VocabularyPragmaticsPhonologySampling learners’ languageSummarySuggestions for further reading3. Individual differences in second language learningPreviewResearch on learner characteristicsIndividual differences and classroom instructionAge and second language learningAge and second language instructionSummarySuggestions for further reading4. Explaining second language learningPreviewThe behaviourist perspectiveThe innatist perspectiveThe cognitive perspectiveThe sociocultural perspectiveSummarySuggestions for further reading5. Observing learning and teaching in the second language classroomPreviewNatural and instructional settingsObservation schemesEthnographySummarySuggestions for further reading6. Second language learning in the classroomPreviewProposals for teachingAssessing the proposalsSummarySuggestions for further reading7. Popular ideas about language learning revisitedPreviewReflecting on the popular ideas: Learning from researchConclusion