Work with the Text Assist feature
Text Assist controls how the onscreen keyboard helps you type. Turn each feature on or off in the Text Assist app (learn how).
Auto-Capitalization: Capitalizes the start of a sentence.
Auto-Correction: Fixes a word as you finish it.
Spell Checking: Underlines a misspelled word and offers corrections above the keyboard.
Predictive Text: Offers the next word above the keyboard. Tap a word to use it.
Checked against the LuneOS code and installed apps. Nobody has tried these steps by hand yet, so tell us if something differs.