Bryan Garner, writing in the original preface for his massive Garner’s Modern English Usage: The Authority on Grammar, Usage, and Style (4th ed., Oxford University Press, 2016):
Not long ago, while I was standing at a rental-car counter in Austin, a young clerk told me that a free upgrade to a Cadillac might be available. She would have to see whether any Cadillacs were on the lot just then.
Two minutes passed as she typed, got on the phone, twirled her hair around her index finger, and then typed some more. Finally I said, “Can I get the upgrade?”
“You mean, ‘May I get the upgrade,’ she responded.
I thought I had imagined it. “What?”
“You said, ‘Can I get the upgrade.’ What you mean is, ‘May I get the upgrade.”
As it happens, I had been working on the manuscript of this book only minutes before, so I couldn’t help thinking how surreal the experience was. I felt a twinge of indignation on the one hand—the kind that anyone feels when corrected. But I also thought that her remark was charming in a way. She was doing her best to uphold good English.
But she was wrong and I gently told her so: “I’m not asking for your permission. I want to know whether you have a Cadillac on the lot. I want to know whether it’s physically possible for me to drive one of them. So: ‘Can I get the upgrade.'”
“Oh, I guess you’re right,” she said with resignation.
Experiences like that one give me hope: they show that some people still care about what happens to our language, however misplaced their concern might occasionally be.