This is a great warmer for younger ESL learners.
How to play: This is a basic game. Tell the students to sit down or stand up a few times, after they get the hang of it, mix it up:
1) Say sit down when they are already sitting down and vice versa
2) Say sit up or stand down.
3) Have a rising voice when you say stand up and a lowering one when you say sit down. Sometimes it's good to switch it so that you have a rising voice when you say sit down and vice versa.