IMPORTANT NOTICE: This site is scheduled for closure in September 2016.
If you have any comments about the closure, please post them to the newsgroup.
See this page for information about the newsgroup and how to post to it.

"mind your p's and q's"

by Mark Israel
 
     [This is a fast-access FAQ excerpt.]

This expression, meaning "be very careful to behave correctly",
has been in use from the 17th century on.  Theories include:  an
admonishment to children learning to write; an admonishment to
typesetters (who had to look at the letters reversed); an
admonishment to seamen not to soil their navy pea-jackets with
their tarred "queues" (pigtails); "mind your pints and quarts";
"mind your prices and quality"; "mind your pieds and queues"
(either feet and pigtails, or two dancing figures that had to be
accurately performed); the substitution of /p/ for "qu" /kw/ in the
speech of uneducated ancient Romans; or the confusion by students
learning both Latin and Ancient Greek of such cognates as pente
and quintus.  And yes, we've heard the joke about the instruction
to new sextons:  "Mind your keys and pews."

   The most plausible explanation is the one given in the latest
edition of Collins English Dictionary:  an alteration of "Mind
your 'please's and 'thank you's".