こそあれ

こそあれ grants that one thing is there and flatly denies its opposite: "if anything X, and certainly no Y". It follows a noun, and the clause after it is negative. A verb takes こと first.

あれ is the classical form of ある that こそ required. It survives in this pattern and never changes shape, whatever the tense of the sentence.

• × 増えるこそあれ → 増えることこそあれ

Granting a difference

Sometimes こそあれ only concedes – "there may be X, but …" – and the second half need not be negative. The set phrase is ていど程度のさ差こそあれ, "to a greater or lesser degree".

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こそあれ is written Japanese: essays, editorials, formal speeches. In conversation, a sentence with ても says the same thing: かんしゃ感謝はしても、うらんでは恨んではいない.