Verb ない form + ものは + Verb ない form

[What can't be done simply can't be done; impossible is impossible]

Connection: Verb ない form + ものは + same verb ない form

Usage: Emphatically states that something simply cannot be done, no matter what. Used to firmly reject a request or possibility by repeating the negative form for emphasis.

Nuance: Conveys finality and determination — there is no room for negotiation or further discussion.

Examples:

できないものはできない。どんなに頼まれても無理だ。(What can't be done can't be done. No matter how much you ask, it's impossible.)

知らないものは知らない。聞かれても答えようがない。(What I don't know, I don't know. Even if asked, I have no way to answer.)

ないものはない。もう売り切れです。(What's gone is gone. It's already sold out.)