Yes.
The kids grumbled about doing their homework, but they eventually got it done. "I can't believe that I have to shovel the driveway again!", Dad grumbled. Grandma did all the cooking and cleaning for the entire family and never once grumbled about it. The teenager grumbled about having to watch his little sister. The kids grumbled as the principal cancelled recess due to rainy weather. He grumbled when I served chicken for the third time that week.
"The man grumbled at the whole scene"
"Grumbled" is the past tense of "grumble".
No, it is a verb, the past tense and past participle of to grumble. The word grumbled is not normally used as an adjective, either.
Mutley
mumbled, jumbled, humbled, tumbled
in that form no, but grumble is. Grumbled is the past tense form of the verb grumble :)
Yelled is not an onomatopoeia:)
Yes it is an onomatopoeia
Yes, adding "ed" to an onomatopoeia does not change its classification as onomatopoeia. Onomatopoeia are words that imitate the sound they represent, and adding "-ed" still reflects a sound.
Yes, yawn is an onomatopoeia.
Yes click is an onomatopoeia