How to Change Languages in Firefox
If you speak English as a second language, using Firefox's language settings can make it easier to understand sites on the Web that support your primary language. The settings are part of Firefox's content management menu, where you can also adjust your preferred fonts and colors. With an extensive list of languages to choose from, there's something for just about anyone -- even if your preferred language is the fictional Klingon of "Star Trek" fame.
Opening the Languages Menu
Click the menu button. It's shaped like a stack of horizontal bars and located in the upper-right section of the browser.
Click the Options button, which is shaped like a gear.
Select the Content tab and click the "Choose" button next to "Choose your preferred language for displaying pages."
Click the "Select a language to add" drop-down menu.
Choose a language from the list. Firefox displays a long list of languages from which to choose.
Click "Add" to add the language to the list. By default, the new language is added to the top of the list, denoting top priority.
Prioritizing and Removing Languages
Select a language on the list.
Click "Move Down" to move the language one space lower on the priority list.
Click "Move Up" to move the language one space higher on the priority list.
Click "Remove" to remove the selected language from the list.
Click "OK" when you've finished adjusting your language settings to save the changes and close the window.