The article respectively introduces how to change language in iPhone and iPad.
Step 1: Open Settings (i.e. the image of a gear).
Step 2: Click General (i.e. a similar gear icon).
Step 3: Select International.
1. If the device's iOS is iOS 6 or earlier, go to the fifth/sixth group of settings and choose the third option, while if it is iOS 7, click the last option in the fifth group of settings.
2. Supposing that there is no such a setting, choose the setting named Multi-language Environment, whose location is the same as that of the International setting.
Step 4: Choose Language (i.e. the first option).
Step 5: Select your target language and tap Done (i.e. the top-right blue option).
Step 1: Enter Settings.
Click the gear icon on the home screen.
Step 2: Find and open General.
Tap the similar gear icon in Settings.
Step 3: Access Internaltional/Multi-language Environment.
Tip: If neither of the above two options is existent in the list, choose Language & Region.
Step 4: Select Language.
Click the first option. BTW, if you open Language & Region, choose Other Languages which is the second option.
Step 5: Choose the object language and hit the top-right option to finish the setting.