Hi Karen
It's hard to know what are fake and what are authentic smurfs when you are not familiar with them. Over time it becomes a lot easier to identify them.
You can check out my website by clicking the www. link at the bottom of my post which shows different types of fakes under each of the authentic smurf. There is also a fantastic website done by Attom who is the legend when it comes to collecting fake smurfs and his websites specialises in just fakes so that would be really worth checking out as well. Here's the link to Attom's website:
http://www.mennoblue.com/
If you are ever in doubt then post a link here and we can always help you as many times as you need until you become more familiar with fakes.
Dyar