The simplest grammar, long thought to be one of the skills that separate man from beast, can be taught to a common songbird, new research suggests.

Starlings learned to differentiate between a regular birdsong "sentence" and one containing a clause or another sentence of warbling, according to a study in Thursday's journal Nature. It took University of California at San Diego psychology researcher Tim Gentner a month and about 15,000 training attempts, with food as a reward, to get the birds to recognize the most basic of grammar in their own bird language.

Yet what they learned may shake up the field of linguistics, according to the Associated Press.

Hey, we talk to the birds all the time. Sometimes they talk back...