乃

• ピンイン: nǎi
• 漢字の分解: 乃 = an ancient pictograph historically meaning 'you' or 'thus' in classical Chinese — now primarily a literary/formal copula or adverb expressing logical consequence or identification

意味

（文語）すなわち／まさに／～である

A classical particle used in formal and literary Chinese. In modern usage, it appears in set expressions, legal documents, and literary writing to mean 'then,' 'thus,' 'to be,' or 'indeed.' Common in four-character idioms and formal prose. Rarely used in ordinary conversation.

例文

1. 失败乃成功之母，每一次挫折都是通往卓越必不可少的积淀与磨砺。
2. 此举乃历史发展之必然趋势，任何试图逆转这一进程的努力都将徒劳无功。
3. 他乃当世少有的全才，无论是文学创作还是科学研究，均造诣颇深。

使い方ガイド

場面: classical Chinese, literary writing, legal documents, set phrases

トーン: literary/solemn

正しい言い方

• 此人乃国内顶尖的网络安全专家，曾多次协助政府机构处理重大信息安全事件。(This person is a top-tier cybersecurity expert in the country, who has assisted government agencies with major information security incidents on multiple occasions.)
• 谦逊乃成大事者应有的品格，盲目自信则往往是走向失败的根源之一。(Humility is the essential character of those who accomplish great things; blind self-confidence is often one of the root causes of failure.)

避ける言い方

• 在口语或非正式写作中单独使用'乃' (乃 is a classical/literary particle — in everyday speech or informal writing, use 是, 就是, or 因此 depending on the intended meaning)

起源と歴史

乃 is an ancient Chinese character appearing in oracle bone script, originally associated with 'you' or 'thus'; grammaticalised into a classical logical particle meaning 'then/thus/is' in formal written Chinese

文化的背景

時代: Classical Chinese

世代: All ages

社会的背景: Universal