Slide two fingers downwards starting from the top the screen.

Tap the settings icon.

Tap System.

Tap Languages and input.

Tap Languages.

Tap Add a language.

Tap the required language to add it to the list of phone languages.

To select the new language as the default language, tap the move icon next to the required language and drag it to the top of the list.

Slide your finger upwards starting from the bottom of the screen to return to the home screen.