“Swang” is used in the American south, particularly the Scotch-Irish areas of the Appalachian upper south. It’s not incorrect but is slipping into archaic status. It’s the simple past form rather than the past participle. It’s also commonly used in the north of England and in Scotland, unsurprisingly as that’s where it arose.
Oh, and “Scotch” is correct, too, by the way.
sing, sang, sung
The borderlands of England and Scotland is certainly where my ancestors came from back around 1650. swung is not a word I use, at least not very often. But my question .........what is the passed tense of swing?