@ Cilyan, that should be fixed by now. If you can try the latest libfm/pcmanfm.
PCMan, thank you. I haven't built the latest yet to test but the one from yesterday had one other thing that wasn't set as translatable. When selecting more than one file/folder, it shows "X items selected" in English. Maybe it's from libfm/src/demo/main-win.c, line 236.