Growing up I had a uncle who could not read or write.
That must have been challenging for him. Was it something that y'all all knew, or was it a well-known "secret"?
The concept of literacy is expanding in OECD countries today. But it was well known he was like that
What is OECD? And did he ever learn to read and write?
The key to literacy is reading development and OECD is the term for learning adults I think.
Ah! And yes to reading. Would any of your uncle's kids or family read to him?
I just think it was different for him. My cousins all can read and write but  Reading development involves a range of complex language underpinnings including awareness of speech sounds. maybe he just never got it you know?