@neil Nonverbal / non-verbal is typically used to describe autistic people who are unable to speak.
Whilst in some cases it does refer to autistic folks who didn't ever learn to communicate verbally, it doesn't mean that such people never learnt other ways to communicate.
For example, a nonverbal autistic person might have learnt to communicate via nonverbal communication (e.g., body language; gestures; facial expressions; etc.).
Additionally, there are nonverbal autistic people who can read and write written language, even if they cannot communicate verbally.
On a side note, the term nonverbal often gets misused by many people, including neurospicy folks, to refer to somebody experiencing a language centre shutdown, such as due to sensory overload or overwhelm, or even a meltdown.
There's a decent write-up by the National Autistic Society here, though it's definitely a very complex topic and goes beyond what even they have written here.
