First, an interview with Vanina Marsot, whose new novel “Foreign Tongue” is about French, English, being bilingual, and translation. It also includes more false cognates than you can hurl a dictionary at, a racy story within a story, and lots of French attitude. Then, a quick detour to Mexico to learn about a Spanish expression that’s favored there. And finally to Afghanistan, where Pentagon acronyms are the lingua franca.