A lot of this kind of reasoning is very visual to me and involves no inner monologue of any kind - just visualizations flying around in my brain in complete silence. The translation into words happens later as a separate step. I wonder if this is not a universal experience.

Some people have no inner monolog, something that blew my mind.

When I work on problems I don't understand I'll monolog it internally. Now when I'm doing things I understand well I have some kind of internal shortcut language (my own token set I guess), that can sometimes make it difficult to explain to other people.

Can you describe how you would reason about say a paragraph of code--something which is very language based?

Depends on what the code is doing! Typically I “see” the underlying concepts or data structures interacting with each other. Imagine those block and arrow diagrams you would have in a textbook explaining how pointers work, except it’s completely automatic for me. My day to day involves a lot of low level systems stuff, so reading a page of code could spawn an image of how various event loops, memory allocations, etc. interact. Then to explain what I’m thinking of to a colleague is sort of like describing what I’m already “seeing” in my mind’s eye. Language to me is just an interface to this inner visual world.