Simple Sentences:
* He muttered a curse under his breath.
* She muttered a reply, barely audible.
* The old man muttered to himself as he walked.
More Complex Sentences:
* Despite her best efforts to remain composed, she muttered a nervous disclaimer as she entered the room.
* As the rain pounded against the window, he muttered about the weather and the inconvenience of having to wait for a ride.
* The children muttered amongst themselves, their whispers growing louder as they became increasingly excited about the surprise.
Figurative Language:
* The wind muttered through the trees, whispering secrets only it could hear.
* The engine muttered and sputtered, threatening to give up entirely.
Remember:
* "Mutter" implies speaking in a low, unclear voice, often expressing dissatisfaction or uncertainty.
* It can also be used figuratively to describe a quiet, continuous sound.