"Relaxed Woman Talking" by autistic artist Miss Luna Rose
Partially verbal autistic people are sometimes able to speak well, and other times find verbal speech difficult or impossible. Speech abilities may depend on stress, cognitive workload, environmental factors, and simply whether it is a good day today.[1]
When they become nonverbal or struggle with speech, they may benefit from forms of augmentative and alternative communication (AAC) such as sign language, typing, picture exchange communication systems, or facilitated communication.
If an ordinarily verbal person loses speech abilities, it may be a sign of autistic burnout.[2][3]