You can easily add another language to keyboard on iPhone or iPad or iPod and switch between different languages. To add new language to iPhone keyboard do as follows:
1. Open the Settings from the main menu
2. Go to the General settings
3. Scroll down to Keyboard settings (it's between Date & Time and Language & Region)
4. Tap the Keyboards option
5. Now tap the Add New Keyboard and find and tap the languages you want to add to the keyboard on iPhone.
TIP: To switch languages on iPhone when typing with the keyboard, tap the Globe icon next to the Space Bar and Mic icon. Tap and hold the Globe icon to see the list of already added languages to the keyboard.