Bikers competing in a race.
There are bikers competing.
No one is competing.
Studying gifted children
All these classes I go to are available on Saturdays.
The child is being swept away by the ocean's current.
A man is on a trampoline alone.
I have a very good job compared to most people
In the circular Temple of Vesta, the sacred flame burned on its own, because it was eternal.