Has spell check changed usage? I type the word "theatre" often; even here while I am typing it is underlined in red, yet Americans who direct, produce, or act in theatre prefer the older spelling.
It's the same with the past perfect, in this example: "By the time he arrived in Chicago, he had had enough sleep in the train to explore the town." Here there is no red underline for "had had," but both Microsoft Word and WordPerfect warn me about them.
How has prescriptive grammar been changed by software companies? How has descriptive grammar been changed by them?