The pyramid game! I've gotta be honest, hasn't really worked for me. 40 kids is just too much going on to make sure that everyone is playing the game the way it is supposed to work.
Basically, you start off at the bottom. Each student takes turns asking the question/answering, then after, they battle (rock,paper,scissors). The winner advances to the next level, and does the same as before, but only with someone on the same level as them. Losers stay on the level and keep trying to advance. In theory, students would be getting a lot of opportunities to speak the key phrases. In actuality, it just turned into a big rock,paper,scissors game for me, with not many students actually speaking the questions unless I walked past them. Still trying different variations to get students to follow the rules better, but I only have 2 more classes playing the game this week so will probably just muddle through it and modify the game later. I can definitely seeing this work though if there are less students in the class.