To be fair, I consider it a foreign language film as well, I was just making the case for it as not one because, for much of it, I felt like I was just listening to English.
The main reason I bring it up is because, I believe if I'm remembering correctly, that both Avatar and Inglorious Basterd made my ballot for Best Non-English Language feature and (maybe) Best Picture, yet I think both only scored Best Picture nominations and most people seemed to scoff at the notion that both were also non-English language films. Wondering why that is overlooked with Certified Copy. I assume, as Sam says, it's because the director wasn't foreign in either case, but I'm not completely on board with that personally.