A person who cannot speak is often referred to as "mute" or "nonverbal." "Mute" is an older term, while "nonverbal" is a more contemporary and respectful way of describing individuals who cannot speak or have significant difficulty with verbal communication. It's important to note that some individuals who are nonverbal may use alternative means of communication, such as sign language, writing, or assistive communication devices, to express themselves and interact with others. Being nonverbal does not indicate a lack of intelligence or capability; it simply means that spoken language is not their primary mode of communication.