I must admit that it is very hard to think of any books like this. I like reading but even I have read barely any books that would fit this description (despite wanting to!). It by Stephen King was already mentioned so I won’t go over that. It seems like the best answer that could be given. It isn’t all about stammering but it plays a big role in the character’s mindset - Black Swan Green is about a secondary school aged boy who stammers and how he tries to fit in with his peers when he moves house and changes school. It is quite easy to read and so I would recommend it - it is told from the boy’s POV so you also get a sense of how he feels about stammering, more than you actually read him stammering (the way that anticipatory feeling is described is very beautiful!) By contrast, another book that technically does fit this description is I, Claudius and the sequel to it - it is historical fiction about the first emperors of Rome (the Julio-Claudians) that utilises the source materials to create a fun but very detailed series of political intrigues and scandalous behaviours as you go through each period, told from the point of view of the 4th Emperor who himself stammered. As a result, it is not even a remote focus of the book, but it is an aspect of it. Also the book is a bit hard to follow if you don’t have a vague handle on who is who or what happened. Finally, a manga, Shino-Chan can’t Say Her Name. This one is pretty short and the focus is stammering but I think the medium itself is utilised very well to illustrate what stammering looks like - you really get a sense of Shino’s anxiety. Sorry! This was too hard.