How do you know if you have forgiven someone?

And

If you forgive them does that mean you act as if nothing ever happened?
I mean f someone shot your dog out of meanness, you might forgive them but would you ever trust them around your dog again? If not does that mean you have not forgiven them?

Suppose you think you have forgiven but you really have not, how would youknow?

Does forgiveness mean you have to associate and be friends with someone that has a personality that just irritates you?

I know these are very childish questions but I really need some answers.