The best stage is from birth to 6 years of age, since children’s brains are at their most flexible during this period. If the second language is acquired with a natural approach, through play, the child will have no difficulty.
Right from birth children are immersed in a family environment where the “mother-tongue language” is spoken and they explicitly adopt what surrounds them. From three years of age the flexibility of children’s brains and their glottal elasticity allow them to attain and reproduce one (or more) new languages without effort. Children develop the ability to use one language or the other either separately or both together, depending on their needs. Mixing the languages up doesn’t mean that the child is confused but rather that the child is capable of using them, depending on the situation and the person he is talking to, as a means of communication in a perfectly interchangeable way.
Bilingual schools observe “rigorous” Italian / English bilingualism and follows the Italian national syllabus. International schools are monolingual and follow the syllabus established by their country.
We are aware of the number and type of requirements, not only in linguistic terms but also in terms of content, that are asked of our children by the best Italian universities, and how possible detachment from and/or lack of the same can be the cause of failure.
The child will be independent where homework is concerned because at school autonomy, along with study method, obviously adapted to each age group, will be one of the main aims.