None of your business is a blunt way of saying that something does not concern you. Conversation over.
It is a rebuff rather than an answer, and it is rude enough that people soften it constantly, so mind your own business and it is a private matter both do the same job with varying degrees of politeness. Saying it flatly ends a friendly exchange. There is a milder version in none of my business, used to preface exactly the sort of comment that follows the phrase.
1phrasenone of your businessUsed to say that something does not concern the person asking.
“How much he earns is none of your business.”
Practised in A Man Called Ove, Small Talk & Everyday Phrases
First appears in chapter 33 of A Man Called Ove.
Practise this word