Not sure if nonverbal is the right word for it, but those that who think not as if they’re speaking in their mind, through some other ways like imagery, feelings, or however.
Often the conscience is described as a little voice in one’s mind saying what’s right/wrong to do, but for those that who think differently, how’s that experienced? Good/bad imagery or feelings instead?
I think the term you’re looking for is internal monologue. I can’t really answer the question, but as I am bilingual I do sometimes catch myself thinking without having an internal monologue and I can tell I’m thinking but haven’t reached a conclusion almost like watching a progress bar while the language part of my brain catches up.