私自

• Pinyin: sī zì
• Hanzi breakdown: 私 = 禾 + 厶 — private, personal; 自 = pictograph of a nose — self, from oneself

Meaning

Without authorisation; on one's own initiative without permission. Describes acting privately and unilaterally in contravention of rules, orders, or agreements.

Carries a distinctly negative connotation — 私自 implies that an action was taken covertly or presumptuously, bypassing proper channels or authority. Frequently used in legal, military, and institutional contexts to describe prohibited unilateral behaviour. Contrasts with 擅自, which emphasises overstepping authority, while 私自 stresses secrecy or lack of consent.

Examples

1. 士兵私自离开营地，违反了军队纪律，依规受到处分。 The soldier left the camp without authorization, violating military discipline, and was punished according to regulations.
2. 她私自修改了合同条款，导致合作方对整个项目的诚信产生了质疑。 She changed the contract terms without permission, causing the partner to doubt the integrity of the entire project.
3. 这名员工私自将公司内部资料发送给竞争对手，已被依法追责。 This employee privately sent internal company materials to a competitor and has been held legally accountable.

Usage Guide

Context: legal, institutional, discipline, formal writing

Tone: critical

Do Say

• 任何人不得私自动用公款，否则将依照相关规定承担法律责任。(No one may use public funds without authorisation; violations will be subject to legal liability in accordance with relevant regulations.)
• 该工程师私自更改了系统核心参数，最终导致整条生产线停摆长达十二小时。(The engineer unilaterally altered core system parameters without permission, ultimately causing the entire production line to shut down for twelve hours.)

Don't Say

• 不要将 私自 用于中性的自主行为 — 它有强烈的负面或批评含义；表示自发主动应改用 主动 或 自行

Origin & History

私 (private, secret) + 自 (self, by oneself) — acting secretly on one's own; without authorisation

Cultural Context

Generation: All ages

Social background: Universal