R has got to be the most magical letter in English. Without it, we wouldn't be able to tell where people are from.

Around the English-speaking world, a P is just a P and a K is just a K, but R changes sound, changes location, and changes in strength. It is the poltergeist of the English language.

Q, we were recently listening to a recording of a PG Wodehouse novel and were bemused to note that Bertie Wooster's awful aunt (the one who eats broken bottles) was called Agather. The favorite aunt, Dahlia, had an R that came and went.