I use Pages quite a bit, one feature that has been annoying me is the predictive text, this is more intrusive than auto-correct, which is useful (for me). No, this is when as you write, Pages suggests which word you are trying to type. Now, I can see how some people might find that useful, however, for me, I find too often that it is not just suggesting the wrong word, but also that act of suggesting actually is both distracting and annoying.
I initially thought it might be in the settings for Pages, but it wasn’t.
From Settings -> Keyboard
Scroll down to Input Sources and click Edit.
Turn off Show inline predictive text.
As this is a Mac wide setting, this “feature” also appears in other applications.