Growing up between two different cultures is no longer a rarity for many people today. In the United States, language developments based on two or more language elements or forms have a decades-long history rooted in an even longer migration policy. For children and adolescents living in densely populated environments, the transition between American culture and that of their homeland is often a given – their living conditions teach them to develop an individual linguistic reality based on various language elements. The influence of two language forms on the linguistic reality of a person or a group of the same ethnic or social origin can have advantages and disadvantages depending on the perspective. Does the mixing of languages lead to confusion and language loss for children, or is a quick switch between languages within a conversation a clever play with their language skills? This book addresses the phenomenon of code-switching against the sociolinguistic background of Puerto Rican communities in New York City.