how!; what!; alas!
Archaic sentence-ending particle expressing exclamation, wonder, or lament. Not used in modern spoken Japanese; appears in classical literature, poetry, and set phrases.
"Alas, how sad!" he lamented.
How beautiful this world is!
In classical literature class, we learned the usage of かな from the poem "Spring has passed, and summer seems to have come; white robes are being dried on heavenly Mount Kagu."
Kanji form used in classical or highly literary contexts; not used in modern everyday writing.
Derived from the classical Japanese sentence-ending particle かな, which combined the interrogative か and the emotive な. Its exact origin is uncertain, but it has been used since the Heian period to express exclamation or wonder.