VATICAN CITY — Just down the hall from the pope's apartment and office in the Apostolic Palace, Carmelite Father Reginald Foster eyeballs processions of Latin words like Caesar reviewing the vaunted 10th Legion before a crucial battle.

This Wisconsin native, plumber's son and graduate of Milwaukee's former St. Anne Parish grade school has come a long way from the world of beer, brats and bubblers.

But not so far that he doesn't still routinely wear plain blue work shirts and pants from J.C. Penney.

He is the pope's senior Latinist, a gifted and demanding linguist who did the lion's share of the translation when Pope Benedict XVI followed tradition and delivered the first formal speech as pontiff in Latin to the cardinals on the morning after being elected.

Known as Father Reggie to some friends and students, he also is an internationally renowned Latin teacher and a fluent speaker of complex, Ciceronian Latin, not to mention a world-class curmudgeon and quirky critic of the temporal and spiritual universes around him. His sometimes intemperate outbursts of personal opinions apparently are offset by an expertise that has enabled him to survive and to serve four popes over 36 years.

Mortals who dare to call Latin a dead language can expect a volley of, "Well, you're just brain-dead. Why don't you just go and talk about chipmunks or hamsters?" One should "dismiss them, ditch them, throw them out" because Latin is "the whole Western world, all of literature, all of language."

His cameo appearances on a weekly Vatican Radio segment dubbed "The Latin Lover" are legendary among some seminarians at the Pontifical North American College, partly because of his reputation for political incorrectness and unpredictability. Computer users can hear Foster tell the story of Rome's founding, burst into liturgical song in Latin, and react to Benedict XVI's first speech on archived shows at www.105live.vaticanradio.org/en_latin.html.

Yet, he also is a monk with a ready smile and a willingness to help visitors to Rome and the students from around the world who take his Latin classes at the Pontifical Gregorian University or his free Latin-immersion course in the summers. He makes the subject come alive through conversation and by doing such things as taking students on the Ides of March — the anniversary of Julius Caesar's assassination — to the site of the stabbing.