〜わけではない
It's not that… (partial negation)machine translation
FormationPlain form + わけではない (な-adjective + な, noun + という)
〜わけではない is PARTIAL negation: "it's not that…, not necessarily." It gently pushes back against what the listener might be misunderstanding, rather than denying it entirely: 日本料理は何でも好きなわけではない (it's not that I like every Japanese dish — some I like, some I don't).
Connection: plain form + わけではない; な-adjectives add な, nouns connect with という. The polite form is わけではありません; in speech it often contracts to わけじゃない. This pattern typically follows a statement of fact, then corrects the interpretation: 忙しいから行けないが、行きたくないわけではない (I can't go because I'm busy — it's not that I don't want to).
Don't confuse it with 〜わけがない: わけがない denies the possibility completely ("there's no way"), while わけではない negates only partially and keeps a soft tone. Compare: 彼が悪いわけがない (there's no way he's at fault) ≠ 彼が悪いわけではない (it's not that he's at fault — though he does bear some responsibility).
Examples
日本料理は何でも好きなわけではない。
It's not that I like every Japanese dish.
忙しいから行けないが、行きたくないわけではない。
I can't go because I'm busy, but it's not that I don't want to go.
お金があれば幸せになれるわけではない。
It's not that having money means you'll be happy.