THE SOLUTION...from NCTexasGirl4048...
I tried this over a week ago and it has worked PERFECTLY ever since, enjoy...
I think I may have found a solution. I recently had the same problem w/ my samsung galaxy s4 Active. I went into settings. I then hit the settings tool icon beside samsung keyboard. Made sure predictive text was on. I actually clicked it off then back on. Then I clicked on the word predictive text and under personalization there are a few learn options. I clicked learn from messages and learn from contacts. I just sent a message and it seemed to fix it! Please let me know if this helps any of ya'll!