For unknown reasons, my google pages (when logged in) were showing up in slovenian. It actually took me a bit of searching just to figure out which language it was; very annoying.
I've tried, a couple of times, to get it fixed, with no success. But yesterday, I finally managed it. When I found the page where you set it, it was set for English, but there was a separate setting (for docs, I think) that was for slovenian. So, I changed that, flushed my browser cookies from google, restarted my browser, and things were finally back to normal. Yay.