I tend to think in images without an internal dialog running. If I think about an upcoming trip I will imagine a series of images related to the trip, possible places to go, or just generally the place. After a bit a potential conclusion appears fully formed in my mind. If I think about a work problem, I might imagine the document, a coworkers face, or something like that while ruminating on it. Basically it feels like the subconscious is handling the details and the conscious self overall directs it.

Occasionally there is some snippet of a sentence I imagine, but it’s almost always cut off prior to finishing the sentence. If I imagine writing something, though, I’ll speak it to myself in my head.

Funnily enough, I’m a pretty weak mental visualiser too. I don’t have aphantasia but metal images are very transparent and dark.