Question

Mind Your P's And Q's to be extremely exact; be careful not to say or do anything wrong; mind your manners

Accepted Answer

Please try to mind your P's and Q's when the princess visits the school. This term was beginning to be used in the 1600s, and by the late 1700s it was very popular. The letters "p" and "q" can often be confused, so children learning to read and printers selecting type have to be careful with these letters. Another possibility comes from old English pubs where a list of the pints ("p's") and quarts ("q's") a drinker consumed were written on a blackboard to be paid for later. Finally, pieds and queues are dance steps that a French dancing instructor would teach his students to perform with care. There's no proof as to where this catchy saying originated, though.

Idiom	Mind Your P's And Q's
Example	Please try to mind your P's and Q's when the princess visits the school.
Meaning	to be extremely exact; be careful not to say or do anything wrong; mind your manners
Origin	This term was beginning to be used in the 1600s, and by the late 1700s it was very popular. The letters "p" and "q" can often be confused, so children learning to read and printers selecting type have to be careful with these letters. Another possibility comes from old English pubs where a list of the pints ("p's") and quarts ("q's") a drinker consumed were written on a blackboard to be paid for later. Finally, pieds and queues are dance steps that a French dancing instructor would teach his students to perform with care. There's no proof as to where this catchy saying originated, though.

Mind P's Q's Careful Princess Visits School Extremely