We all have days when we are just plumb tired. You probably all know how to say, 「つかれた。」 But why use tired language to describe being tired? Let's excite things up with two gitaigo (mimesis) action words:
shigoto de hetoheto desu.
I'm exhausted from work.
But what if you are VERY tired and へとへと just doesn't cut it? Try ぐったり out for size.
be dead tired