Ok, I have find a shortcut method, open the link below.
and simply change the language to English, after about 2 seconds the page will reload automatically and the default language from now on will be English.
Click here: https://www.facebook.com/settings?tab=language
If you are prompted to sign into your account, please do.
On the right hand side, there will be an edit option. Click on it and you should see English in the list of languages.