The book Dual Language Development and Disorders: A Handbook on Bilingualism and Second Language Learning (3rd Edition) provides a comprehensive overview of bilingual and second language development in children. It emphasizes that dual language development is a natural and beneficial process, offering children cognitive, social, and cultural advantages. The book distinguishes between simultaneous bilinguals (learning two languages from birth) and sequential bilinguals (learning a second language after establishing the first), considering factors such as language status (majority or minority) and age of acquisition. It addresses key concepts like heritage language maintenance, code-mixing, and the interplay of sociolinguistic and neurocognitive factors in language development. Additionally, the authors explore language disorders in bilingual children, emphasizing the importance of culturally and linguistically informed assessment and intervention practices. Case studies highlight the diverse profiles of bilingual learners, from internationally adopted children to those in immersion programs. The book targets a broad audience, including educators, speech-language pathologists, and parents, aiming to dispel misconceptions about bilingualism as a deficit. Instead, it positions dual language development as an asset, advocating for informed decisions regarding education and intervention strategies for bilingual children.