When early in life children learning first language, the brain that parts of brain tissue will be used for all the languages. Whereas, if children are exposed to languages later in life, different parts of the brain are involved because the part of the brain that is responsible for processing language is on a maturational timetable and know very clearly what that timetable is, when the periods are most sensitive. But this is not the case for all the parts of language. Some parts remain open for life, like vocabulary and there are other parts of language, which are on a maturational timetable. Our brain reaches a stable processing capacity and then stops because it’s achieved it’s stable state. It’s quite hard to determine when this happens because the different parts of language are affected differently by maturation.