On the Home screen, tap Settings.
On the next screen, tap General.
Select Language & Region
Scroll down and tap Language & Region.
Tap Device language
On the next screen, tap "[Device] Language".
Select your language
Pick your language from the list.
Confirm your selection
An alert will ask you to confirm the new language. Tap the first option.
After your device updates the language, your device should automatically display the language you selected.