Elia’s comment > Likes and Comments

I read this book when I was eleven and understood it perfectly fine. The capability of a reader at any age is completely relative to how much experience they have reading, and shouldn't be taken into account. As a matter of fact, the idea of an eleven year old wanting to read Ender's Game might lead one to reason that the child is fairly intelligent and might be looking forward to the challenge.
Well, it could also be the fact that this awesome movie came out about a genius kid and OP's son never actually saw the book...

I don't remember any foul language. Although, you do raise a good point about the Locke and Demosthenes bit.