Wondrous Words Wednesday is hosted by Bermudaonion’s Weblog. Kathy says: “Wondrous Words Wednesday is a weekly meme where we share new (to us) words that we’ve encountered in our reading.”

For the second week in a row, my Wondrous Words Wednesday post comes courtesy of Watching the English by Kate Fox.

I’ve heard the phrase “mind your Ps and Qs” but I never fully understood it. I knew at one point that it had to do with pints and quarts in pubs, so I thought it was the same thing as my fifth grade math teacher saying “watch your units.” And, yet, I also knew that English parents said it in the same tone of voice and same situations as my parents said, “I expect you to be on your best behavior.”

This quote on page 150 of Watching the English was the first time that I grasped how Ps and Qs could stand in for pleases and thank yous:

The English may not speak much on public transport, but when they do open their mouths, the words you are most likely to hear, apart from ‘sorry’, are ‘please’ and ‘thank you’ (the latter often shortened to ‘ ‘anks’ or ‘ ‘kyou’). During the research for this book, I made a point of counting these Ps and Qs.

The Wikipedia article, Mind your Ps and Qs,  says that the origins of the phrase are obscure and mentions both the pints and quarts thing and the pleases and thank yous. Another interesting possibility is from the printing press — ps and qs being easy to erroneously swap.