I have a text document, and the words within certain blocks cannot be changed. If I click on a word, the whole text block is chosen.
How can I undo that, and only chose a single word?

Your description suggests you have a document with formfields and/or cross-references. Without seeing the document, though, it's hard to be sure.

Can you attach a document to a post with some representative data (delete anything sensitive)? You do this via the paperclip symbol on the 'Go Advanced' tab.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

These sound like protected content controls.