An Ameraucana has a Standard it MUST meet and the standard can be found on the Ameraucana breeders club site. If your bird does not meet all of the requirements and is not one of the 8 accepted colors then you have an EE. If you got your birds from any hatchery that lists the chicks as Americana/Araucana it is an EE. I mean no disrespect to anyone but I really do not see what is so confusing, this topic has been beaten to death on this site, like Jean said if you use the search tool you will find hundreds of posts on this subject.
some real easy explainations about EEs and Ameraucana, like are they really that much different? Yes they are.
And if so how can you tell and be SURE? Is it possible to selectively breed EEs and get a showable Ameraucana? <---because if so that will explain why it's so hard to tell the diff LOL. They only way you can be sure is to buy from a reputable breeder and preferably one that is a member of the breeds respective club so you know they are legit. I personally do not think it is difficult to tell the difference. If familiarize yourself with the standard and the accepted colors then you should have no troubles.
Many get confused on the spellings too Very true. Ameraucana (note no i) and Araucana.
it would also be neat to see every color recognized in each purebred as theres not that many at least not in Ameraucanas Ameraucana come in 8 recognized varieties at them moment and that is actually quite a lot. The Araucana Club and the Ameraucana Club sites have photos of all recognized colors in both Bantam and Large Fowl.