I could have also used this for P--but here's my Q.
How many times have you said "watch your P's and Q's and really didn't know where the saying came from?
Well I was very curious and have been studying this phrase the past week.
I found the following explanations from Wickepedia but no one can know for sure the true origination.
1. Parents have used this to stand for "p" being please and "q"- being for excuse me-the q sounding like ex-cuse. P and Q being easier for them to pronounce.
2. A possibility from English bartenders in the seventeenth century, they would keep an eye on the alcohol consumption of their customers. They watched how many pints and quarts were consumed.
They would say to the patrons "watch your "ps" and "q's.
3. Maybe it came from sailors in the eighteen century who were reminded to pay attention to their peas (pea coat) and queues (pony tail).
4. This origin I think is more than likely the origin--it comes from the early printing presses. Printers placed individual letters on a frame to print a page of text. If the letters were reversed (they are right next to each other) it would be easy to mis-spell a word. They were fined for every spelling mistake!!! I can easily see how you would remind those to watch their "ps" and "qs".
I think of our children when they are learning the alphabet how easy it is to mixed these letters up!!!
There have been books written on this subject if you want to learn more!!
Linking with ABC Wednesday