The multilingual mind : a modular processing perspective This book is the first detailed description of a particular theoretical framework for studying language development and language performance. The framework is called MOGUL (Modular On line Growth and Use of Language). It has been the topic of numerous publications and presentations since the appearance of our 2004 keynote article in Bilingualism: Language & Cognition. MOGUL is not just about how a language grows in the individual child: it is about how the mind expands to accommodate more than one language both in childhood and later in life and how these various linguistic systems share space and interact