This is a lesson plan for students preparing for the Cambridge main suite exams. I specifically created it with C1 or C2 students in mind but it could easily be adapted to B2. Students practice word formation while playing a game of noughts and crosses. Download the handout below:
Students play in pairs, they must choose a square on the board where they want to place their token, but they must first correctly complete the corresponding word formation question in order to do so. All of the words are based on the same root word.
If a student answers incorrectly, you could either have the opponent steal the square by answering correctly, or say that the square is now dead and nobody can place a token there.
As a follow-up you could set your students the task of coming up with their own lists of nine sentences to use in future games. You could give them each a root word (use, communicate, etc.) and send them to the Longman Online Dictionary to look up all the derivatives in order to make their 9 questions: https://www.ldoceonline.com/