Can somebody say how to go to challenges or give any link?
First of go to setting then manage weapon and switch on the languages for challenges. In which you want to challenge other or want to be challenged.
select the play section in the bottom of your phone navigation and Click on the plus and select the user and the language whom you want to challenge
Now click on play (at bottom strip) Click on + Choose a language. Choose opponent. Answer the questions. Wait for result.