Language Alerts, or a brief example of a language that morphs.
Old pulp magazines, their copyrights expired, have been digitized and uploaded, as an example.
Reading one story, the captain of the craft, something transpired in the plot, and the team responded alertly, rather than alert, and in the context? It was the most correct form. However, in the ensuing years, the adverb form has shifted dropping the “ly,” necessitating a language alert.
The old grammar gods are rolling in their graves.