English Thread

In this thread, we attempt to learn to read, write, and speak English, a language which would be very useful to know. It is widely spoken throughout the world.

Do you speak English? Are you fluent? What resources did you use to learn? Can you give some examples in this thread? Posts some useful links.

Let's help each other out and learn a new language.

"Police have appealed for witnesses to the accident."

I don't understand the last part of this sentence. I mean "to the accident". Why is there "to" instead of "of"? I can understand "the witnesses of the accident", but I don't understand "the witnesses to the accident".