In this chapter, we aim to summarize the range of work that has been and continues to be conducted on multilingual populations from various theoretical paradigms and/or distinct subareas of theoretical and applied linguistics. Any attempt to be exhaustive in this regard would be doomed from the start, as space – and likely the attention of the reader – would surely be an obstacle. Moreover, and of equal importance, doing so would distract us from the main goal of this book, which is to understand the dynamic nature of representational morphosyntactic transfer in adult multilingualism and the manifold theoretical implications that derive from revealing this. That being said, it is important to understand the larger context in which our choice of focus is situated and thus appreciate the piece of the larger puzzle that it is. Therefore, this chapter serves to provide a cursory snapshot of the puzzle itself.