Mind your Ps and Qs
Definition 1 of 1
Pro Tip 1/3Cultural Politeness
Represents awareness of social etiquette and cultural norms of politeness in English-speaking contexts. 
He's new in England, so he's learning to mind his Ps and Qs in different social situations.
Pro Tip 2/3Not Literal
This phrase is an idiom, meaning it's not about actual letters but about good behavior. 
My grandma always told me to mind my Ps and Qs, not just the alphabet.
Pro Tip 3/3Respectful Contexts
Use it when in formal settings or showing respect, especially among those of higher status or age. 
Mind your Ps and Qs at the dinner with the company's CEO tonight.