This book explores a type of bilingual acquisition – early sequential bimodal bilingual acquisition – in Hong Kong Sign Language (HKSL) and oral Cantonese, by adopting data from a deaf child who acquired HKSL from birth and Cantonese from around age 2 after cochlear implantation. One main goal of this book is to verify if the developmental trajectories and acquisition processes such as crosslinguistic interaction resemble those documented in monolingual acquisition. The associated acquisition processes are accounted for with reference to the Language Synthesis Model (Lillo-Martin et al 2016) which is built upon the theory of Distributed Morphology.