"Which ball is yours?"
Translation:Kiu pilko estas la via?
kiu pilk la vias?(can i treat via like an old adjective? this might already of been covered but ive decided to stop reviewing abandon timidity and boldy march forward...)
You can't put a verb ending on every adjective and use it like it means "to be + adjective". Doing that will make you write "Mi rapidas" for "I'm fast" when it actually means "I'm hurrying".