When you go work in a soup kitchen for free, this is an example of a situation where you volunteer.
A person who works in a soup kitchen for free is an example of a volunteer.
An information booth staffed by volunteers; hospital volunteers.
Volunteer firefighters; volunteer tutoring.
Volunteered their services; volunteer to give blood.
We were volunteered to do the dishes.
Many retirees volunteer in community service and day care centers.
To volunteer for doing the dishes.
My sister volunteered me to do the dishes.