Ofcourse you can forgive but only someone who has done harm to you. You can't forgive who has done harm to others. You have no right to do that.
It is better for you to forgive someone who has done wrong to you. And after that not reminding him/her that you have forgiven. That chapter needs to be closed forever. Forgive and forget (because you want to be forgiven as well).
The Weak can never forgive. Forgiveness is an attribute of the Strong." - Ghandi.