All components of the keyboard are controlled by iOS, including multi-language keyboards, Auto-Correction, Check Spelling, and Predictive text. These features can be turned on and off in iPhone Settings > General > Keyboard. Please note, if these features aren’t working, this is an issue with iOS.
If you added another keyboard, you can access it by tapping on the globe in the bottom corner of the keyboard.
If you’re experiencing slowness in typing, changing keyboards, or adding emoji, please reset your keyboard dictionary via iPhone Settings > General > Reset > Reset Keyboard Dictionary.
To learn more about the keyboard on your iPhone, please visit the Apple Support website.