My husband, Peter, is learning Spanish his own way.I do Duolingo online. It is free. It is easy to do. The whole thing is designed like a game, and dancing animated creatures hop up and down and celebrate every time I get five answers in a row correct.This shouldn’t matter to me—yet I find it deeply satisfying. Peter doesn’t do any of this.Peter learns Spanish by talking with the sandwich shop staff.Since we started staying in our little apartment in Mexico, Jorge, the resourceful owner, has converted what used to be a storage room into a sandwich shop.The sandwich shop ...