If your phone gets service, yes you can make a phone call. It will more than likely say "Roaming" and may cost you an arm and a leg, however I don't know what "normal American plan" you have.
It would likely be MUCH cheaper if you simply purchased a local SIM card to switch with your Verizon SIM card while you are in Europe. You would have to give anyone you wanted to get in touch with you your new European #, though.
With your "normal American plan", you would be paying $3/minute for any calls. If you subscribed to the international plan, that would drop to $1.79/minute.
MUCH lower if you purchase a local SIM card.
You could also purchase a SIM card from Amazon...
Amazon.com: international sim card - SIM Cards & Tools / Accessories: Cell Phones & Accessories
You still must have a pay as you go international plan added to your features.