Multilingual Doc Defies Spell Checker

[Pinkham, Jim]

I've got a book with documents that have Brazilian, Spanish, German, and
perhaps UK English ancestries. I've tried selecting paragraphs and using
the Paragraph Designer to set to U.S. English. This does not seem to be
working flawlessly, despite trying across-the-board updates of paragraph
types. For an entire document such as this, it would seem to be
intuitive that there has to be a better way. Is there? And, if so, what
is the correct process to get it all into U.S. English so the spell
checker works appropriately?