The QuickType keyboard in iOS 8 promises to be Apple's "smartest keyboard ever," but its Predictive word suggestion feature can be distracting to iPhone owners who are not used to using it. Luckily there is an option to disable the feature if you do not like it. Here's how:
To disable Apple's Predictive QuickType Keyboard option navigate to Settings > General > Keyboard. Tap the "Predictive" slider so it turns white / OFF.