The article focuses on the description of one of the main features of current multilingualism and its complexity through a selection of issues related to its role in L2 acquisition, seen as a social and multidimensional phenomenon. Nowadays, multilingualism is one of the most relevant social phenomena, and therefore, it is an issue of utmost interest both for study and research, given the large amount of studies from different fields and disciplines. Learning a second or any other additional language might occur in any learning environment and it is always bound to external and internal factors, however, very little is still known about their influence on the language acquisition process. Bilingual or multilingual children acquire and learn languages at a very early age and they gain unprecedented experiences, which might be considered a valuable treasure and heritage for the future of the society.