meaning of 'mind your p's and q's'?

[falling slowly]

Dear teachers~!
A text says 'mind your p's and q's' means 'pay up'.
but another text says it means 'watch your mouth'
what is the right meaning?
both of them are right?

[RonBee]

Mind your p's and q's means mind your manners, which could mean watch what you say.

[bhaisahab]

Dear teachers~!
A text says 'mind your p's and q's' means 'pay up'.
but another text says it means 'watch your mouth'
what is the right meaning?
both of them are right?

I think it's an old British English expression, mind your p's (please) and q's (thankyou's). In other words, be polite.

[amigos4]

One possible explanation: It is advice to children learning to write to take care not to mix up the lower-case letters p and q.

[Raymott]

One possible explanation: It is advice to children learning to write to take care not to mix up the lower-case letters p and q.

I've always taken this to mean "be careful; don't mess up" rather than any moral meaning.
I believe it was derived from earlier times when printers had to stack lead print letters into racks - it was easy to mix up p's and q's because they had to put them in backwards." It still means (metaphorically) the same thing.

[BobK]

That's the most convincing version I've heard too. It's always struck me that the 'please/thank yous' one was probably invented by Victorian governesses! (Governess - Wikipedia, the free encyclopedia)

b

[bhaisahab]

That's the most convincing version I've heard too. It's always struck me that the 'please/thank yous' one was probably invented by Victorian governesses! (Governess - Wikipedia, the free encyclopedia)

b

Yes, you could be right there.