This compelling book compares and contrasts the emergence of intentional and symbolic communication in both chronologically and developmentally young children, and in older individuals who are functioning at early language levels. Practicing and aspiring professionals will explore the critical transition periods in typical and atypical development, learn how foundational skills may affect future language development, and discover valuable methods of building communicative competence, fostering communication alternatives for challenging behaviors, including caregivers in assessment and intervention, creating positive learning environments, and providing responsive communication partners. Practical and informative, this accessible text provides a balance of theory, research findings, and strategic intervention models, and offers analyses of prelinguistic assessment and intervention approaches with a strong emphasis on clinical and educational implications. It is ideal for speech-language pathologists, special educators, early childhood professionals, psychologists, and graduate students looking for a research-based clinical guide to understanding and encouraging the transitions from preintentional to intentional and from presymbolic to symbolic communication.