When a cow isn't a cow.

My Finnish-American grandson is a charmer. At eighteen months, he's doing everything he should be doing: exhausting his parents, pestering his older sister, learning something new every day, running, trying to feed himself, and playing with new sounds. One of his favorite words is "cow."

Now, even though he says "cow," and says it with great relish, he isn't really talking about a cow. In the Finnish language, that combination of sounds doesn't mean anything at all, and we know that when...