It depends. If I'm "in the zone", there's nothing verbal about it. I stop seeing the screen or feeling the keyboard and the code just flows forth. I do have a mental imagery in the form of geometric shapes, but that's about it.<p>If I'm not "in the zone", then I verbalize a lot either with my actual voice or in my head, stating out loud what the immediate problem I'm solving is and walking through the steps I'm taking.
It's maybe 10% strictly verbal, and that only when I'm having trouble. More significantly, I make very heavy use of fully formed multi-word camel case variable names. It's much like speaking out loud. It is hugely useful, and the compiler doesn't care.
I’d say it’s about 50/50. It’s verbal when considering what to name variables, styling the code, and ensuring I didn’t make any mistakes. When considering the flow of the code, and what pieces to put where, it’s more intuitive.