 Hot seat. This is a great activity that can be used as a warm-up at the beginning of a class, or as a game at the end of a lesson. It's suitable for any class size over four students and requires minimal preparation. Divide the class into two teams, and have two chairs at the front of the class, set up to face away from the board. Have one student from each team come and sit in the chairs, and tell them not to turn and look at the board. The premise of the game, is for you to write a word or expression from your lesson on the board, and have the students facing away from the board guess what it is. Give each team 10 points to start with, and tell them if they break any rules, points will be deducted. The rules must include no miming, you want students to give verbal clues, and no use of their own language. Other students call out clues, and whichever of the students at the front guesses correctly first gets the point. Have other students replace them each time. This is a fun game that can get quite noisy. You might want to exert some control, by giving each team 15 second chunks to give clues. Stop your rules as you see fit.