I have a problem every day.
I have an everyday problem.
It’s a problem involving people who don’t distinguish between everyday and every day.
“Everyday is an adjective, meaning it describes a noun,” observes the inimitable copy editor Sarah C. Jones. “As in, My everyday routine includes eating doughnuts.”
She continues: “Every day is not the same thing, grammatically speaking. As in, I am getting fatter every day thanks to my everyday doughnut-eating routine.”
Thank you for this helpful observation, Sarah. (Oh, by the way, you have a little sugar on your chin.)