There is no such thing as Google En Francais per se. Google.fr, the French version of the Google search engine, does not translate all webpages into French.
Google.fr is more likely to return search results that are already in French because Google attempts to deliver results that are relevant to its users.
In addition, Google Chrome, Google’s browser, has a built in translation feature. If it is able to detect that a user is viewing a webpage that is not in his native language, a prompt appears offering to translate it. However, it does not work for all pages and translations are imperfect, often containing mistakes in grammar and diction.
Finally, Google Translate can translate blocks of text for users. These translations are susceptible to the same mistakes in grammar and diction as translations from Google Chrome.