Good boy

My dog knows a lot of stuff.
I asked him about sandpaper, and he said “ROUGH”
But I think I found undeniable proof.
When I pointed to my house, and he yelled “ROOF”
Then I thought I was going deaf
When we watched football, and he said “REF”
After that came the moment of truth
When I asked the capital of Minnesota and he said “DULUTH”
I know, I know. It’s St. Paul.
Stupid dog.