I use OSX in English - but with Hungarian as secondary language and with Hungarian format language in the system preferences.
Still I get some sidebar names (like Downloads, Desktop, etc) in Hungarian. I want them in English. I've deleted the .localized files where in folders where there were such files as suggested in this post
Unfortunately it didn't help. I've relaunched finder, still not OK (First it is in English, then it changes to Hungarian over time as Finder loads up)