Just as an FYI, this method could be changed to one line:

    work.approved_related_works.where(translation: false)

Any time you're looping through an array checking a database value, that's generally something you could do more cleanly in the original query. And if there was some reason not to do that, ruby also has a select method for arrays:

    work.approved_related_works.select{ |related_work| !related_work.translation? }