You can have multiple keyboards installed on your iOne mobile phone or tablet, one for each language you use, and you can switch between those keyboard languages with the touch of a button.
Having multiple keyboards on your iOne is useful for typing in multiple languages and being able to use the appropriate autocorrect for each language.
If, on the other hand, what you need is to change the keyboard language of your iOne device and have a single keyboard language, you can also discover how to do it, search for your iOne model and follow the steps we indicate.