Verb conjugation of "acaparar" in Spanish

In the meantime I am listening to some Spanish CDs. They are intended for the car, but no one can tell you when to listen to it, how many times and how often. Please understand that I work a lot.
Joanna started kindergarten 2 weeks ago. She got used to it very quickly and I must say that I am very pround of her. She is now 23 months old and we are going to celebrate her birthday in three weeks.
Usually I do not care too much about not getting change, but when you pay a 3 dollar ride with 50 dollars, you do actually expect change. We stood there for a while and neither of us knew what to do.