How do you say "Merry Christmas" in English?

Today I let my kids decorate Christmas cards. I fool myself into thinking it’s English practice: all they do is color the letters “Merry Christmas” and fill in the “To” and “From” blanks. And still one of my first graders asks me how you say Merry Christmas in English (they say the same thing, in a Korean accent, in Korean). Man, I am an amazingly effective teacher. It’s funny to see how the kids change over the years—the first graders all wrote to either mom, dad, or mom and dad, the fourth graders almost all wrote to their parents (one, inexplicably, wanted to write to Jack Sparrow…), about half of the fifth graders wrote to their parents and half wrote to friends, and almost all the sixth graders wrote to their friends. Guess it’s not “cool” at their age to communicate with or make anything for Mom and Dad. I wonder if they even give their cards to their friends or just throw them away. Not that I care, really…they get to have fun for forty minutes, and I get a chance to relax for once. Only two more days. Seven more classes.