Use this game for teaching:

"Can you...?"

"Yes, I can"

"No,I can't".

These actions are fun:

wiggle
dance
run quickly
hop
skip
do a star jump
do a handstand
touch your toes
cross your eyes
snap your fingers
whistle
sing

E.g. Ask a Student "Can you cross your eyes?".

If the Student replies "Yes, I can" then say "Ok, go!" and the Student does the action.

If the Student says "No, I can't", say "Too bad. Ok, can you (wiggle)?"