this conversation has already been had. English is not an easy language to learn. If you learn one Romance language, it can easily be moved to another Romance language. If you look at spanish, and the amount of irregular verbs, there really aren't that many. Look at English and the amount of irregular verbs. Good luck with that. I agree though that after being completely immersed in it for a number of months a year, he should be able to have a passable conversation.