Simple:
* My grandfather is very grumpy in the morning.
* The cat looked grumpy after being woken up.
Descriptive:
* The grumpy old man sat alone on the park bench, scowling at the children playing.
* After a long day at work, she came home feeling grumpy and tired.
Figurative:
* The weather has been so grumpy lately, with nothing but rain and wind.
* The old house looked grumpy and neglected, with peeling paint and overgrown weeds.
In dialogue:
* "Don't be so grumpy," said the little girl, "It's your birthday!"
* "I'm just a little grumpy," he mumbled, "I didn't get enough sleep."