Deep End
← Grammar guides

Level Advanced Chinese · HSK 5–6

Rules, Warnings and Requests: 无, 未, 勿, 非…不可, 禁止, 务必, 免得 and 尽量

Signs, rules and contracts compress a lot into very few characters. Their negatives and modal words are the written forms of everyday 没, 不, 别 and 一定要. Knowing them lets you read any notice and write a formal request.

Written negatives

无 (wú) = 没有: 无人 (no one), 无关 (unrelated), 无法 (unable to). 未 (wèi) = 没 / 还没: 未成年人 (minors), 尚未 (not yet). 勿 (wù) = 别 / 不要, on signs and in polite requests: 请勿吸烟 (please do not smoke). 非 (fēi) = 不是: 非卖品 (not for sale).

非…不可 (fēi … bùkě) means 'absolutely must': 这件事非你去不可 (you're the only one who can go). It's emphatic and used in speech too.

WrittenSpokenExample
无没有无人值守 (unstaffed)
未没 / 还没未经允许 (without permission)
勿别 / 不要请勿触摸 (please do not touch)
非不是非工作人员 (non-staff)

  • 未经允许，请勿拍照。

    Wèi jīng yǔnxǔ, qǐng wù pāi zhào.

    Please do not take photographs without permission.

  • 这个手术非做不可。

    Zhège shǒushù fēi zuò bùkě.

    This operation absolutely has to be done.

Prohibitions and strong advice

禁止 (jìnzhǐ, prohibited) and 严禁 (yánjìn, strictly prohibited) appear on signs and in rules. 不得 (bùdé) means 'must not' in regulations and contracts: 不得转让 (may not be transferred). 不准 (bùzhǔn) is the plainer, more everyday 'not allowed' (不准停车 on a hand-written sign, 妈妈不准我去 at home).

务必 (wùbì) means 'must, be sure to' in formal requests: 请务必准时参加. 千万 (qiānwàn) is the spoken 'whatever you do', usually with 别 or 要. 切记 (qièjì) means 'be sure to remember'.

Contracts also use 应 (yīng, shall), 须 (xū, must) and 有权 (yǒuquán, be entitled to).

  • 公共场所严禁吸烟。

    Gōnggòng chǎngsuǒ yánjìn xī yān.

    Smoking is strictly prohibited in public places.

  • 请务必在周五前回复。

    Qǐng wùbì zài zhōuwǔ qián huífù.

    Please be sure to reply by Friday.

  • 你千万别告诉别人。

    Nǐ qiānwàn bié gàosu biéren.

    Whatever you do, don't tell anyone.

免得 / 省得, 一旦 / 万一 and the 尽 family

免得 (miǎnde) and 省得 (shěngde) mean 'so as not to, to avoid': they open the second clause. 多带件衣服，免得着凉 (take an extra layer so you don't catch cold). 省得 is more colloquial and often means saving trouble. 以防 (yǐfáng, in case) is the written equivalent.

尽量 (jǐnliàng) means 'as far as possible'; 尽快 (jǐnkuài), 尽早 (jǐnzǎo) and 尽可能 (jǐn kěnéng) mean 'as soon / early / much as possible'. 尽力 (jìnlì, do one's best) is read with fourth tone.

Safety instructions use 一旦 (once, in the event that) and 万一 (in case) with 应急 (emergency): 一旦发生火灾，请立即撤离.

  • 出门前看看天气预报，免得被雨淋。

    Chū mén qián kànkan tiānqì yùbào, miǎnde bèi yǔ lín.

    Check the forecast before you go out so you don't get caught in the rain.

  • 请尽快把材料发给我。

    Qǐng jǐnkuài bǎ cáiliào fā gěi wǒ.

    Please send me the materials as soon as possible.

Common mistakes

  • ✗请勿不要吸烟。

    ✓请勿吸烟。

    Qǐng wù xī yān.

    勿 already means 'don't'. Doubling it with 不要 is a double negative.

  • ✗我非去。

    ✓我非去不可。

    Wǒ fēi qù bùkě.

    The standard pattern is 非…不可. (Colloquially 非 + verb alone can mean 'insist on', but it's best to use the full frame.)

  • ✗我们尽力完成任务尽快。

    ✓我们会尽快完成任务。

    Wǒmen huì jǐnkuài wánchéng rènwu.

    尽快 is an adverb before the verb, not after it like English 'as soon as possible'.

Questions learners ask

Is 尽 in 尽量 the same character as in 尽力?

Yes, but read differently: jǐn in 尽量, 尽快, 尽早 and 尽管; jìn in 尽力, 尽头 and 尽心.

Can I say 请勿 in an email?

It sounds like a sign. In a polite email, write 请不要 or rephrase positively.

Practice this in lessons

The Advanced Chinese lessons teach this step by step, with exercises and review built in.

Practice this in lessons →

Related grammar guides