It’s actually more that the Old Norse and Old English had different endings and the Vikings didn’t bother to figure out the English system. I don’t think they k

It’s actually more that the Old Norse and Old English had different endings and the Vikings didn’t bother to figure out the English system. I don’t think they know whether the -s is from a Norse ending or whether the Norse settled on -s for other reasons. The simplified version eventually spread because England was a mixture of various ethnicities for centuries and you’d have different variants of English from one town to the next— and after the Vikings you had the normans. I think it’s the equivalent of the guy I was eating with at a restaurant in Nicaragua who yelled to the waitress ‘honey, el forko por favor?’ Like, there was an attempt at Spanish.