Hangul syllable ggic

Press Shift+R, then L, then C on the Korean two-set layout.

That key sequence enters ㄲ, ㅣ and ㅊ. A Korean input method editor (IME) combines the Hangul jamo—the letter components—into one block as you type. On the South Korean two-set layout, each physical key maps to one component.

If the parts stay split, the input method may be outputting jamo separately, or the app or font may not shape a decomposed sequence into one block. Use Korean syllable-composing input; key assignments differ on other layouts.

What does 낓 mean by itself?

Alone, it does not reveal the sender's intent.

낓 is one Hangul syllable block made from ㄲ, ㅣ and final ㅊ. Hangul syllables usually join into words, whose surrounding letters provide meaning; this lone block may be a fragment, an input test, or accidental typing. Ask the sender which they meant.

Why does final ㅊ sound like t at a word's end?

At a word's end, final ㅊ is an unreleased t-like stop.

At the end of a Korean word, ㅊ closes the mouth like a short t and is not released as “ch.” Before a following vowel, it can link to the next syllable and sound like ㅊ at its start.

Hangul was created in 1443 and introduced in a 1446 guide to the new alphabet. It gave Korean readers an alphabet designed for their language, alongside the earlier practice of adapting Chinese characters to write Korean. Its blocks group consonants and vowels by syllable, as in 낓. Some scholars argue that the Mongolian Phags-pa script influenced Hangul's shapes, but that link remains disputed. Chinese characters used in Korean, called Hanja, belong to that earlier writing context; they are not the source of 낓's sound structure.