How to Add a Language to a Keyboard on Android
If you use a phone that doesn’t have a standard version of Android running on it, the options here may appear in slightly different places, but the general process is similar. You can also change the system language on Android. To add a language to an Android keyboard:
How to Add and Switch Language Keyboards in iOS
Follow these instructions on Apple iOS devices—iPhones, iPads, and iPod touch devices—running iOS 9 through iOS 13 to add keyboard support for additional languages.
How to Add and Use Different Language Keyboards on Windows
Follow these instructions on any computer running Windows 10 to add keyboard support for additional languages.
How to Add and Use Language Keyboards on macOS
Follow these instructions on Apple computers running macOS to add keyboard support for additional languages.
How to Add Language Keyboards on Chrome OS
Follow these instructions on devices running Chrome 76 (or newer) to enable keyboard support for additional languages in Chrome OS.