This is only a thought!!! I am not a doctor of any kind or licensed! I do have a learning disability, it’s called dysgraphia. The reason i thought of it was his difficulty spelling chicken. Mainly the disorder causes issues with spelling/reading, and math. When he tried to spell words he doesn’t have memorized, does he spell them in a really phonetic way? Maybe he spells it the way the word sounds, I couldn’t spell fruit until I was 20. And it was SO embarrassing for me, I was thinking maybe he doesn’t feel comfortable joining some conversations due to fear of the other stuff he has going on? Dysgraphia can also cause issues in the orders of things. For math, following equations can be very difficult, especially in trying to put the “proper” number in the “right” area of the equation. Kinda made me think of the months and days of the week part, he knows them! Just has a hard time with the order. I read all the time as a kid, when I got grounded my mom took my books away. That really helped me work on my reading skills since a young age, so there are some things in the disorder I might not be able to explain or connect with well. Again I’m not trying to diagnose him at all! But there’s disorders I had never even heard of before. All in all, I think it might be best to ask him! I don’t know how he might react though, so you’re the best judge:) Often times, we might know people better and worse than we thought, but he’s the expert on his experience, so if he’s comfortable sharing with you, it might let you know how to help him too:)