Age of Acquisition
The significance of accent
The critical Period Hypothesis
Hemispheric Lateralization
Right hemisphere participation
Anthropological Evidence
Neurological consideration
Biological Tymetables
Cognitive considerations 
Jean Piaget outlined the course of intellectual development in a child through various stages
Sensorimotor stage (birth to two)
Preoperational stage (ages two to seven)
Operational stage (ages seven to sixteen)
Formal operational stage (ages eleven to sixteen)
Concrete operational stage (ages seven to eleven
Affective considerations
Linguistic considerations
Bilingualism
Code switching
Coordinate Bilinguals
Compound Bilingual
Have two meaning system from both languages
Have one meaning system from both languages
Interference in adults learning process as a second language
Order of acquisition
Children learning process as a second language use a creative construction
Issues in the first language adquisition
Competence and performance
Comprehension and production
Sistematicity and variability
Language and thought
Imitation
Discourse
Practice
Universal
Nature and nurture
Interference Between first and second languages
Dispelling myths
Language learning is mainly a matter of imitation
We must practice and practice
First, we practice the separate sounds, then words and at the end sentences
First listen and then speak
The natural order for first and second language is listening, speaking, reading and writing.
You did not have to translate
A child does not learn formal grammar