Did Elijah use informal words like dad, okay, or um.
I think he did.
Most of us do, and James1 thought he was like the rest of us.
Are informal words from Elijah “anachronisms”?
I don’t think so. I think of anachronisms as belonging in a different time than Elijah’s, such as airplane or computer. People of all times have used dad, okay, or um.
I suspect books and movies which portray hyper spiritual Biblical characters speaking King James English from an echo chamber have warped our understanding.