Hangul syllable jjyo

On a Korean input method, enter ㅉ, then ㅛ.

On the standard Korean keyboard layout, Shift+W enters ㅉ and Y enters ㅛ. The input method joins those component letters into the single syllable block 쬬.

What does 쬬 mean?

It is an older Hangul spelling linked to modern 쪼.

Hangul, the Korean alphabet, arranges consonant and vowel letters into square syllable blocks. 쬬 is the block made from consonant ㅉ and vowel ㅛ.

Hangul was devised in 1443, and its explanatory book was published in 1446. The system let Korean speakers write their language with its own letters rather than relying only on Chinese characters.

The distinction represented by this spelling was meaningful in the 15th–16th centuries; it blurred in the 17th century and was largely settled by the 18th century. In this change, older 쬬 corresponds to modern 쪼, alongside parallel changes such as 쨔→짜, 쪄→쩌, and 쮸→쭈.

Why did old Korean encodings miss 쬬?

Some older tables had no slot for this syllable.

A 1990 National Institute of Korean Language article about the KS C 5601 complete-type Hangul code table lists 쬬 among five omitted syllables. Complete-type tables assigned a slot to each whole syllable block; a compositional font could instead build one from its letters.

On a system relying on that table, the missing slot could block input or display; a compositional system could build the syllable if its font supported the parts. If an old file shows a blank or replacement character, suspect the encoding or font support: the spelling itself did not change.