I have a friend who works as a volunteer. ✬

The magician asked for a volunteer from the audience. ✬

As a punishment, the disgraced Greenpeace volunteer had to scrub oil from an otter's fur with his own toothbrush. ✬

Since I have no children, I have more time to spend doing volunteer work than parents do. ✬

Have you ever done any volunteer work? ✬

Tom doesn't have much time for volunteer work. ✬

Tom does volunteer work. ✬

Tom does a lot of volunteer work. ✬

Tom didn't volunteer to be a guinea pig. ✬

Tom certainly isn't going to volunteer. ✬