I have been unabashedly contemptuous of previous stories about dogs learning to understand human languages (for example, I hammered home the point that fetching named objects is not understanding language in this 2004 post, which Mark Liberman followed up here). I think it is incumbent on me to acknowledge further developments in the area that actually lead to refereed publications, so let me point out that Learning and Motivation has now published a paper about some experiments purporting to show that a 9-year-old border collie called Chaser has learned some rudimentary syntax. For example, Chaser can differentiate To ball take Frisbee from its inverse, To Frisbee take ball, and perform the right action in each case. This Science News article gives a fairly full account of the results.
Me? I honestly don't know what I think about this yet. Maybe you want to comment below? I'm cool with that. Remember, though, that on the Internet nobody knows you're a dog, so if you are a dog, please admit it; it's a matter of declaring your interest in the controversy.