Cats know too much

Do you mind explaining the difference?

Sure! In ABA, verbal behavior is essentially any kind of communication such as speaking, using sign language, pointing or gesturing, etc. Therefore, saying that someone is non-verbal implies that they cannot communicate at all, which is highly unlikely. Instead, we would say that a person is non-vocal if they cannot speak. For example, I work with many clients who are non-vocal, but talk to me through sign language or an APP.

Sidenote: we do use the term non-verbal but only to describe things that can't communicate. For example, if we say a behavior is controlled by "nonverbal stimuli," we could be talking about an object, smell, sound, etc. (but NOT a person).