Explore each form from the oldest known stage to today.
Historical forms are not available yet. The current form is shown as a reference.
The kanji "効" (kō, "effective") is a variant form of the character "效", which itself is composed of two primary components. The character is classified as a phono-semantic compound (形声文字, keisei moji). The left radical, 交 (kō, "to mix; cross"), primarily provides phonetic value, indicating the pronunciation. The right component, 攵 (the "strike" or "action" radical, a variant of 攴), provides the semantic meaning, denoting an action or the application of force. Thus, the core etymological meaning is "to apply an action to produce a result" or "to put into effect." Historically, "效" (and by extension "効") evolved from the concept of "to imitate" or "to model after," as seen in words like 模倣 (mohō, "imitation"). This sense of "following a model to produce a result" naturally extended to mean "to be effective" or "to produce an intended effect." The character's development can be traced through Chinese script evolution, from ancient seal scripts to the more regularized clerical and standard scripts. The simplified form "効" emerged as a common clerical variant in China and was the form that became standardized in Japan. This character, along with the broader Chinese writing system, was introduced to Japan via the Korean Peninsula around the 5th century AD. It was adopted into the Japanese language as part of the on'yomi (Chinese-reading) lexicon. An interesting linguistic note is that while "効" and "效" are used interchangeably in Japanese for "effectiveness," Japanese orthography officially standardized on "効" for most common words, such as 効果 (kōka, "effect") and 有効 (yūkō, "valid"). This distinguishes it from modern Chinese, which uses "效," highlighting a divergence in character standardization practices between the two languages.