how can I change default language to english

Hi * In the Menu bar at the top of the screen, click Firefox and select Settings (or Preferences, in some cases). * If you can't read the language Firefox is currently using, type about:preferences#languages in the address bar to open the Settings section Languages directly. * Select Languages on the left and go to the Browser language section. Choose a language in the drop-down menus Preferred languages and Fallback language, if available. * Restart Firefox. More info: [https://support.mozilla.org/en-US/kb/use-firefox-another-language#firefox:mac:fx159 Use Firefox in another language]