To change the game language, you need to tap on the Settings (gear icon) at the upper right of the home screen. It will take you to the Settings screen from where you can change it to your preferred language.
The game may be played in the following languages:
The game will validate words using the dictionary corresponding to the language you select in the Settings.
If you're playing with a player that is using a different language, the language set by the player initiating the game will be used to play the game.