Turn 1:
ENEMY used WHATEVER!
It did something!
CHIMECHO used YAWN!
CHIMECHO made ENEMY drowsy!

Turn 2:
CHIMECHO used PROTECT!
CHIMECHO protected itself!
ENEMY used WHATEVER!
CHIMECHO is protecting itself!
ENEMY fell asleep!

Yawn makes the target fall asleep at the end of the next turn, the same time that poisoned and burned pokémon are taking damage and such.