It's Christmas! Celebrate by not doing violence to the laws of pluralization. Photo illustration by Slate. Photo by DK-photo/iStock. Nothing quells my Christmas cheer as quickly as a stray apostrophe.

The other day I received a Christmas card addressed to "The Diorio's." It made the grammar grinch in me flinch. The way the card was addressed was incorrect. Unless the sender was writing to our house ...