since yesterday my firefox thinks that everyone in belgium speaks flemish. this is a typically american problem: americans NEVER seem to know where languages are spoken (i think they just guess) but for some reason believe that language localization software is cool. it is NOT, it is a curse. so suddenly i no longer have my user interface in english (which was fine) but now in flemish, which looks and reads like a tongue disease and is not even the second language of the area i live in (first language here is german, second is french). how can i change back to english?
You should install an English language pack. A language pack is a Firefox add-on.
You can download it from here. Then you must install it like any other add-on ("install add-on from file" in the add-on interface).
Then you should change the language preference. You can do this by typing about:config in the Location bar (address bar) and then searching for
And change that to:
(the same name as the downloaded .xpi) Then you must restart the browser.
More details at: http://kb.mozillazine.org/Language_packs