了

Pictographic origin, later serving as a phonetic loan.

The ancient forms depict a child (子) emerging from a womb or enclosure, symbolizing “completion” or “something brought to an end.”

Over time, 了 came to represent both the idea of ending (completion) and, by phonetic extension, meanings associated with clarity or understanding.

In Shuowen Jiezi (說文解字):

「了，明也。从子。象子在母腹中形。」

“了 means brightness or understanding. It is derived from 子 (child), picturing the form of a child in the womb.”

Originally, the sense of “completion” was derived from childbirth — the process coming to an end and something new being realized.

Evolution of meaning:

Classical sense: “to understand, to perceive clearly.”

Derived sense: “to finish, to bring to an end.”

Modern Chinese: grammaticalized into aspect marker (了) indicating completed action or change of state.

了解 (요해) — to comprehend, to understand clearly

明了 (명료) — clear, lucid, obvious

未了 (미료) — unfinished, incomplete

終了 (종료) — to finish, to bring to an end (ending element -了)

In Korean usage, 了 generally retains its lexical meaning of completion or clarity, not its Chinese grammatical usage.

Usage in Chinese language

Verb:

了 (liǎo) — to finish, to complete, to understand.

事情了。 — “The matter is finished.”

明了其理。 — “He understood the principle clearly.”

Particle (modern Mandarin):

了 (liǎo / le) — marks completed action or change of state.

我吃了飯。 — “I have eaten.”

天黑了。 — “It has become dark.”

As part of other characters or compounds:

瞭 (liǎo) — bright, clear (original full form).

瞭解 (liǎojiě) — to understand (clarity-related).

了結 (liǎojié) — to settle, bring to conclusion.

Simplification note:

In modern Chinese, 了 serves as a simplified substitution for 瞭 when pronounced liǎo (“understand, clear”), but not for liào (“bright, shining”) — where the full form 瞭 is still used.

Related characters:

瞭 (밝을 료) — clarity, brightness; full form of 了.

完 (완) — to complete, finish.

畢 (필) — to accomplish fully.

竟 (경) — to reach the end, finally.

Over millennia, it shifted from concrete to abstract, and from lexical to grammatical use — now serving as the key aspect particle in modern Chinese while still preserving its classical meanings of clarity and completion in Korean and literary Chinese.

It is a quintessential example of a simple graph with profound semantic history — a character of closure, realization, and enlightenment.