- On the Home screen, tap Settings. It's the icon that looks like a gear.
- On the next screen, tap General. It's the option with a similar gear.
- Using iOS 8 or later: Scroll all the way to the end of the list and tap Language & Region. It's the option just before the one that starts with "iTunes".
- On the next screen, tap "[Device] Language". It's the first option.
- Pick your language from the list. Then tap Done, the word or words in blue in the upper right corner.
- An alert will ask you to confirm the new language. Tap the first option.
After a few seconds, your device should return to the Home screen and display the language you selected.