"A redundant that is sometimes used after where, what, and similar conjunctions."
The quote from the Dictionary of Smoky Mountain English is a fancy way of saying we use a lot of thats in Appalachia.
- I don't know why that he thinks he can get away with that. I mean good grief they're not blind they're going to see what he's doing.
- Do you know when that they are going to start moving over to the new store?
- When they pulled up I was telling him how that I had been the one taking care of the place for the last several years.
I most often hear the redundant that used with the word how. Wait a minute let me clarify that-I actually don't hear it. I don't ever 'hear' the extra that when I'm listening to someone speak because the usage is so common in my area. The only time I actually notice the usage is in my own writing-I really like the word that but I bet you've already figured that out.