In iOS 11, you can access a specialist keyboard designed for one-handing typing. When in use, the keyboard shifts the keys over to one side of the screen so it’s easier to type with just one hand.
To open it, go to an app or website where you are able to enter text – such as an email or iMessage. Then hold down your finger on the globe icon (or the emoji icon if you’ve that keyboard setup.)
Choose which side you want the keyboard on from the options provided. To go back to the regular-sized keyboard, simply tap the arrow on the empty side of the keyboard.