1. Nature
2. Differente levels for description and analysis
3. First language
3.1. Acquiring the L1
3.1.1. Two important factors
3.1.2. Developmental sequences
3.1.2.1. First three years
3.1.2.1.1. Grammatical morphenes
3.1.2.1.2. Negation
3.1.2.1.3. Questions
3.1.2.2. Pre-school years
3.1.2.2.1. Metalinguistic awarenes
3.1.2.3. School years
3.1.2.3.1. Reading, Language registers
3.2. Monolingualism
3.3. The logical problem of language learning
3.3.1. Innate capacity
4. Second language
4.1. Distinctions
4.1.1. Foreign language
4.1.2. Library language
4.1.3. Auxiliary language
4.1.4. Language for specific purpose
4.2. The world of second language
4.2.1. Multilingualism
4.2.1.1. Simultaneous bilingualism
4.2.1.2. Sequential multilingualism
4.2.2. SLA vs SLL
4.3. Frameworks to explain SLA
4.3.1. Linguistic approach
4.3.1.1. Early approaches
4.3.1.1.1. Contrastive analysis
4.3.1.1.2. Error analysis
4.3.1.2. Internal focus
4.3.1.2.1. Transformational generative grammar
4.3.1.3. External focus
4.3.1.3.1. Functionalism
4.3.2. Cognitive approach
4.3.2.1. Early psichological models
4.3.2.1.1. Behaviorism
4.3.2.2. Computational models
4.3.2.2.1. Information processing
4.3.2.3. Emergentism
4.3.2.3.1. Tennets
4.3.2.3.2. Connectionism
4.3.2.3.3. Neuropsychological accounts of SLA
4.3.3. Social explanations
4.3.3.1. Sociocultural theory
4.3.3.1.1. Role of language
4.3.3.1.2. Interpersonal interaction
4.3.3.1.3. Intrapersonal interaction
4.3.3.2. Factors
4.3.3.2.1. Microsocial
4.3.3.2.2. Macrosocial
4.3.3.3. Contexts
4.3.3.3.1. Natural setting
4.3.3.3.2. Educational setting