Multilingualism is one of the central themes in current linguistic and psycholinguistic debates. Additionally, multilingualism is a relevant topic in educational discussions and language policies across the world, even in the context of less studied languages such as Czech. This book highlights the multiple facets of multilingualism by presenting a number of original studies and reviews exploring this topic from a wide range of perspectives, including empirical, pedagogical, and language-teaching studies. The methodological approaches reach from linguistic descriptions and qualitative surveys to experimental methods used in infant research. The book shows that individual multilingualism is a decisive factor for language processing, language acquisition and learning as well as language pedagogy. The book provides novel insights both for the discourse on multilingualism in general, and the Czech language specifically, inside and outside of the Czech Republic.