You might consider Tok Pisin, the official language of Papua New Guinea. It's actually a creolized Pidgin English, which has the advantages (especially for your purposes) of having an easily acquired vocabulary and a syntax that is substantially English, but substantially simplified. Just remember that p is f (or ph) and sound the words out loud, and it makes much more sense (e.g. "aggressive person" = "man bilong pait" = "man belong fight" = "man characterized by fighting".)