► Chapter 4 examined the transformative impact of augmentative and alternative communication (AAC) systems and brain-computer interfaces (BCIs) in enhancing communication for individuals with severe motor impairments. These technologies enable interaction through limited muscle control, such as eye movements. However, a significant gap persists for those in a completely locked-in state (CLIS) due to conditions like amyotrophic lateral sclerosis (ALS), where eye fixation is lost, leaving individuals unable to communicate. This chapter addresses whether fluent word and sentence formation is achievable in CLIS. It begins by exploring the neurobiological foundations of speech production, offering insights into how the brain processes and generates language. This understanding is critical for developing technologies capable of bypassing neuromuscular impairments. The discussion then reviews recent advancements in speech-decoding technologies, emphasizing invasive BCIs. These systems, which involve surgical implantation, create direct brain-to-device communication pathways, potentially restoring communication for individuals in CLIS. By synthesizing neurobiological knowledge and the latest technological innovations, the chapter aims to provide a comprehensive response to the question posed in ► Chap. 4 : “Is fluent communication possible for individuals in CLIS?” It offers hope for the future of communication technologies for those facing the most profound physical limitations.