During office discussion two turns of phrase came up in close proximity: "peace and quiet" shortly followed by "mind your P's and Q's".

What is the meaning of P's and Q's? I wondered if it might be related to peace and quiet.

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    This one is a classic. Like "the whole nine yards," there are many suggested etymologies, e.g., printer's type, pints and quarts, etc. Still disputed. – The Raven Apr 4 '11 at 17:44
  • I think I may have come across this in World of Warcraft! That's the only place that rings a bell else first time I've heard it! Mae govannen! – MalsR May 31 '11 at 12:52
  • @TheRaven 'Nine Yards' often refers to a 'Sari', a traditional indian female dress. It typically is nine-yards long. It's possible it's derived from there. – mikhailcazi Sep 3 '13 at 7:24
  • The term is expressed using small letters as p's and q's rather than with majuscules, P's and Q's which reflects incorrect usage. Detailed explanation from the printing trade is given in the Answers. – Stan Mar 22 '18 at 1:51

"Mind your Ps and Qs" means "be careful to behave well and avoid giving offense."
The NOAD reports that its origin is unknown; it would refer to the care a young student must take in differentiating the tailed letters p and q.

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    What does NOAD refer to? – John K Feb 10 '11 at 1:58
  • The exact sentence used by the NOAD is said by some to refer to the care a young student […]. – kiamlaluno Feb 10 '11 at 2:12
  • I mean what does the NOAD acronym mean? – John K Feb 10 '11 at 2:32
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    I am sorry; I didn't understand. It's the New Oxford American Dictionary, the equivalent for American English of the Oxford English Dictionary (OED). – kiamlaluno Feb 10 '11 at 2:36
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    @Phil. Similar idea; different meaning. That's about being careful in general, wheras minding your p's and q's is specifically about being polite. – TRiG Mar 9 '12 at 15:31

I've always heard that it was originally short for "Mind your Pints and Quarts!" Something an innkeeper (or what-have-you) would shout to an unruly common room to settle them down. According to AUE no one's particularly sure, but they list a few other theories, including what they consider to be the most likely: "Mind your 'please's and 'thank you's".

Link: http://alt-usage-english.org/excerpts/fxmindyo.html

  • +1 This is the only answer that gives an origin/etymology! I've heard this same origin (the pints and quarts one - the other seems dubious). The other interesting origin is to do with the printing press. – Noldorin Feb 10 '11 at 16:47

It means

Be on your best behaviour; be careful of your language.

The date of the coinage of 'mind your Ps and Qs' is uncertain. There is a citation from Thomas Dekker's play, The Untrussing of the Humorous Poet, 1602, which appears to be the earliest use of the expression:


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    In particular I know it to mean "be polite", I was often told that it meant " P lease and Thank- Q s" [sic]. – Orbling Feb 10 '11 at 1:54
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    @Orbling: Certainly, it's always been please and thank yous in my mind for as long as I can remember. – Jimi Oke Feb 10 '11 at 4:40
  • @All, yep "Please and thanQs" for me too. – Benjol Feb 10 '11 at 9:01
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    As a general rule, any etymology that involves abbreviations and predates about 1940 is false. – Malvolio Mar 16 '11 at 19:43

I read somewhere that it came about, ages ago, to remind people in the printing business, to be careful when typesetting 'p' and 'q', because it was easy to confuse the two. In general, this would mean to take extra care with what you were doing. Now, it appears to have several meanings including:

  • Mind what you say

  • Mind your manners, specifically 'pleases' and 'thank yous'

  • Mind your own business

All of which are related.

I wonder if it would be acceptable to use 'mind your Ps and Qs' to mean take extra care with what you are doing? I have never heard the phrase used in that context.


Anyone who has worked as a printer's devil knows the answer to the origin (and meaning) of the elderly term, "Mind your p's and q's."

I must preface my remarks on the origin of the term with brief background.

First. The origin of the printing process using moveable type around mid 16th century was made possible by using individual molded glyphs that were the mirror-image of the desired printed image. The nature of each individual glyph is that similarity exists among several different ones; notably, the p, q, d, and b. The difference is the orientation of the glyph. As it turns out, tiny letter decorations called serifs make telling one character from the other easier. The sole exceptions are the p and q. Their only different characteristic is that one is reversed—the mirror of the other.

Second. Each different letter used is kept sorted in a multi-compartment drawer referred to as a type "case" organized by frequency-of-use. Thus, "e" and "t" are near the centre of the case and less-frequently used letters such as "v" and "j" are near the sides. This is done for speedy and correct page composition.

In use, the typesetter composes a document letter-by-letter, line-by-line to fill a page. After the page is printed, the type block is cleaned, removed from the "chase," taken apart line-by-line, letter-by-letter and distributed back into the proper compartment in the type case for re-use. Majuscules (capital letters) go in one case and minuscules (small letters) into another placed slightly below the other. All this is done completely in reverse by a skilled apprentice referred to as "a printer's devil."

Most all this can be accomplished simply if not easily "by feel" until you run into the two most-easily confused glyphs where you must pay special attention to keep them correctly sorted by heeding the admonition to "Mind your p's and q's."


There are many theories, (some of them given in answers here) but none of them has any supporting evidence whatever. WorldWideWords has an article.


It's to do with the fact that children often confuse the small 'p' with the small 'q' when learning how to write and read (like they do with b's and d's.) So if taken literally it is basically an appeal to 'be careful, be precise, listen to what you teacher has told you' - which comes pretty close to its use in language (i.e. mothers with their children.)

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    -1 This is one of many suggested etymologies. – The Raven Apr 4 '11 at 18:10
  • ...I didn't realise there was a problem with p's and q's like that. I guess some people aren't taught that q has a pointy tail...? I mixed up my cursive g's and q's because of it, but never my print p's and q's. Hmm. – kitukwfyer Apr 4 '11 at 18:22

Another theory I have heard - probably apocryphal - is that it has to do with the two branches of the Celtic family of languages: P-celtic (i.e. Brythonic - Welsh etc.) and Q-celtic (i.e. Goideilic - Irish etc.). It was said to date from when these were beginning to separate and you had to get the pronunciation right in each area to be understood.

To be honest this sounds rather unlikely as why would it be an idiom in English - a language from a completely different family.

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    This could only be true if those languages were called by those names at the time that the idiom was coined. And generally when languages are beginning to separate you don't need to be too careful about pronunciation since you'll still be understood. – Mr. Shiny and New 安宇 Apr 4 '11 at 18:04

I've always understood as a warning to be polite. And I've always seen it this way:

Mind your P's and Q's as in your "Pleases" (P's) and "Thank-yous"(Q's), thus the origin of P's and Q's... I don't know if anyone else has the same notion?

  • That's what my mother meant when she said it to me. – Kit Z. Fox Jul 29 '11 at 18:27

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