(Rachel Feltman’s article appeared in the Washington Post, 3/8.)
When it comes to human language, syntax — the set of rules for arranging words and phrases to impart meaning — is important. People might understand what you meant if you declared "to the store I go must," but your phrasing wouldn't seem quite right. And saying "must store go the I to" wouldn't get you anywhere at all, even though the same six short words were in play.
But sometimes we use syntax to impart complex combinations of ideas. "Careful, it's dangerous" is a phrase that has meaning, and so is "come toward me." When those two phrases are combined, they have a different meaning than they do on their own: They're directing the receiver to act in a different way than either phrase would independently.
Until now, only humans seemed to use syntax this way. But a study published Tuesday in Nature Communications suggests that the Japanese great tit — a bird closely related to the North American chickadee — uses grammatical rules like these in its calls.