The Language Pack is a software add-on that changes the display language of Office 2016 applications (Word, Excel, PowerPoint, Outlook, etc.) to English. Crucially, it does translate document content; it translates menus, ribbons, dialog boxes, help files, and proofing tools (spelling/grammar) to English.
For individual developers or power users, the next best legitimate source is an active (formerly MSDN). Microsoft provides the same pristine 64-bit language pack images here. If you are a student via Azure for Education, you also have access. microsoft office 2016 english language pack 64bit best