板上钉钉

1. Basic Information

• Pinyin: bǎn shàng dìng dīng
• English Translation: Driving a nail into a board (a done deal / set in stone)
• Idiom Composition: 「板」（Board; referring to a hard wooden or stone plank.）＋「上」（On; upon.）＋「钉」（To nail; the action of driving a nail (verb).）＋「钉」（Nail; the metal fastener (noun).）
• Meaning: A colloquial expression describing something that is final, settled, and unchangeable, much like a nail driven firmly into a wooden board.

2. Detailed Meaning and Nuances

「板上钉钉」 contains the following nuances:

• Absolute Certainty: It emphasizes that something is not just a plan or a high probability, but a finalized decision with zero chance of being overturned.
• Colloquial Tone: It is frequently used in daily conversation or informal discussions to assert that something is 'settled' or 'a sure thing' rather than in formal legal documents.

3. Usage

「板上钉钉」 is mainly used in the following contexts:

• Finalizing Plans or Decisions: Used to inform others that a schedule, personnel change, or contract has been finalized and can no longer be modified.
  • Example:「这次的人事调动已经是板上钉钉的事了，谁也改变不了。」
    （This personnel transfer is already a done deal, and no one can change it.）
• Emphasizing Facts: Used to highlight that evidence is conclusive or that a fact is universally recognized, leaving no room for doubt.
  • Example:「证据确凿，他是凶手这件事已经是板上钉钉了。」
    （The evidence is conclusive; it is an indisputable fact that he is the culprit.）

Additional Examples:

1. 别再犹豫了，这笔生意已经是板上钉钉，跑不掉了。
   （Don't hesitate anymore; this deal is already set in stone and won't slip away.）
2. 虽然大家都这么说，但在官方宣布之前，这还算不上板上钉钉。
   （Even though everyone is saying so, it can't be considered final until the official announcement.）
3. 只要合同一签，这事儿就是板上钉钉了。
   （Once the contract is signed, this matter will be settled once and for all.）
4. 明天的会议取消是板上钉钉的，不用再去确认了。
   （The cancellation of tomorrow's meeting is certain, so there's no need to check again.）

4. Cultural Background and Notes

• Pronunciation Note: The second 钉 (dīng) is often pronounced with a neutral tone (ding) in this idiom. In Northern dialects, it is frequently spoken with an 'er' sound at the end as 板上钉钉儿 (bǎn shàng dìng dīngr).
• Variation: Sometimes 铁板钉钉 (tiě bǎn dìng dīng) is used. Since driving a nail into an iron plate (铁板 - tiě bǎn) is even harder than wood, it implies an even stronger degree of unchangeable certainty.
• Origin: It appears in the Qing Dynasty (清) novel *Qi Lu Deng* (歧路灯). Originally, it was 'driving a nail into a stone slab,' implying that while difficult to drive in, once it is there, it is permanent and as solid as an inscription in stone.

5. Similar and Opposite Idioms

• Similar Idioms:
  • 千真万确 (qiān zhēn wàn què): Absolutely true; an undeniable fact.
  • 雷打不动 (léi dǎ bú dòng): Unshakeable; a plan or determination so firm that even a thunderstrike cannot move it.
  • 一成不变 (yī chéng bù biàn): To remain unchanged; to be set in one's ways.link
• Opposite Idioms:
  • 变幻莫测 (biàn huàn mò cè): Unpredictable and constantly changing.link
  • 未定之天 (wèi dìng zhī tiān): Still up in the air; an undecided state.
  • 变化无常 (biàn huà wú cháng): Constantly changing and unpredictable.link
  • 模棱两可 (mó léng liǎng kě): To be ambiguous or equivocal, having two or more possible meanings.link

6. Summary

板上钉钉 (bǎn shàng dìng dīng) is used to emphasize that a decision, fact, or agreement is completely finalized and cannot be altered. The visual image of a nail driven into a board suggests a permanent fixture that is difficult to remove, representing absolute certainty in daily conversation or business contexts.