When do I use 否则 vs 不然 vs 要不?

Use 否则 in formal writing and serious warnings. Use 不然 in neutral contexts—spoken or written—to mean 'otherwise'. Use 要不 in casual speech, especially to propose a suggestion or alternative. The key is formality and function: 否则 is formal, 不然 is neutral, and 要不 is colloquial.

Can 要不 and 不然 be used interchangeably?

They can both mean 'otherwise' in informal speech, but 要不 is more common for suggestions, while 不然 is neutral for consequences. For example, '要不我们去看电影？' (suggestion) sounds natural with 要不, while '不然会无聊' (otherwise it'll be boring) works better with 不然. In many contexts they overlap, but careful use of nuance improves naturalness.

Is 否则 used in everyday conversation?

Rarely. 否则 is very formal and is mostly found in official announcements, contracts, and academic writing. In daily talk, native speakers prefer 不然 or 要不. Using 否则 would sound like reading a legal document.

How do I express 'otherwise' in a conditional sentence (if...otherwise)?

In formal Chinese, you can use '如果...否则', e.g., '如果你不努力，否则就会失败' is redundant. Instead, say '如果你不努力，（那）就会失败' or simply use 否则 after the condition: '如果不努力，否则就会失败' is acceptable but 否则 alone implies the condition. In neutral or informal contexts, use '不然' after the first clause without 如果, e.g., '快点，不然我们迟到了'.

Easily confusedHSK 4

否则 vs 不然 vs 要不: three ways to say 'otherwise'

In Chinese, 否则, 不然, and 要不 all translate to 'otherwise' or 'or else', but they differ in register and function. 否则 is formal and literary, used in serious consequences. 不然 is neutral and can be used in most contexts. 要不 is colloquial and often suggests an alternative proposal rather than a negative outcome. Understanding these nuances helps you sound natural and avoid awkward mistakes.

The three terms all indicate an alternative outcome if a condition is not met, but they belong to different registers and serve distinct discourse functions. 否则 is the most formal and is typically used in written warnings, official documents, and serious statements of consequence. 不然 is neutral and versatile, appearing in both spoken and written language to express 'otherwise' without a strong stylistic bias. 要不 is informal and frequently introduces a suggestion or alternative course of action, making it less about consequence and more about proposing a different option. Choosing the right one depends on the level of formality and whether you are stating a consequence or making a suggestion.

각각 언제 쓰는지

否则fǒu zé

otherwise (formal/written)

Use 否则 in formal or written contexts to indicate a consequence that will happen if a condition is not fulfilled. It is common in official documents, academic writing, announcements, and serious warnings. The condition is often expressed with 如果 or 假如 in the preceding clause, but can also be implied.

否则 can sound stiff or overly serious in casual conversation; it is rarely used in everyday speech among friends.

不然bù rán

otherwise / or else (neutral)

Use 不然 in everyday speech and writing to express 'otherwise' when the consequence is clear. It is neutral in register, so it works well in most situations—from casual chats to standard written Chinese. 不然 can also stand alone as a response meaning 'no' or 'not necessary'.

When used alone, 不然 can express disagreement or offer an alternative opinion, e.g., 不然呢？('Or what?'). It is less formal than 否则 but more formal than 要不 in suggestion contexts.

要不yào bù

or else / how about (colloquial suggestion)

Use 要不 in casual conversation to propose an alternative or make a suggestion. It often means 'how about' or 'why don't we', rather than simply stating a negative consequence. 要不 is common in friendly discussions, plans, and compromises.

While 要不 can also mean 'otherwise' (similar to 不然), its primary function in speech is to introduce a new idea, not just to warn of a consequence. When used to mean 'otherwise', it is informal and usually implies a mild consequence.

한눈에 보기

	否则	不然	要不
Register / Formality	Formal, literary	Neutral, versatile	Informal, colloquial
Primary function	Express a serious consequence	Express a consequence or confirm an alternative	Propose a suggestion or alternative
Typical context	Official documents, warnings, academic writing	Everyday speech and writing, both formal and informal	Casual conversation, friendly suggestions
Usage with condition clause	Often paired with 如果/假如, condition explicit or implied	May follow a conditional clause, but often used alone after command	Rarely used with explicit condition; stands alone as suggestion

예문

否则
请按时完成任务，否则将影响整个项目。
Qǐng àn shí wán chéng rèn wu, fǒu zé jiāng yǐng xiǎng zhěng gè xiàng mù.
Please complete the task on time, otherwise it will affect the entire project.
Formal warning; 否则 is appropriate for official instructions.
不然
快走吧，不然会迟到。
Kuài zǒu ba, bù rán huì chí dào.
Hurry up, otherwise we'll be late.
Neutral, natural in everyday speech; 不然 is correct here.
要不
我们去看电影吧？要不唱歌也行。
Wǒ men qù kàn diàn yǐng ba? yào bú chàng gē yě xíng.
Shall we go to the movies? Or we could sing instead.
要不 introduces a suggestion, not a negative consequence.
否则
你必须遵守法律，否则就会受到惩罚。
Nǐ bì xū zūn shǒu fǎ lǜ, fǒu zé jiù huì shòu dào chéng fá.
You must obey the law, otherwise you will be punished.
Formal consequence; 否者 (common mistake) is incorrect.
不然
下雨了，不然我们可以出去玩。
Xià yǔ le, bù rán wǒ men kě yǐ chū qù wán.
It's raining, otherwise we could go out and play.
不然 expresses a counterfactual consequence; natural and neutral.
要不
要不我们换个地方吃饭？
Yào bù wǒ men huàn gè dì fāng chī fàn?
How about we eat at another place?
Colloquial suggestion; 要不 is ideal here, not 否则 or 不然.

흔한 실수

Using 否则 in casual conversation sounds stiff and unnatural; use 不然 or 要不 instead.
Using 要不 to state a serious consequence (e.g., 'otherwise you will die') is inappropriate because 要不 suggests a mild alternative, not a grave outcome.
Mixing 如果 (if) and 不然 in the same clause creates redundancy, e.g., '如果...不然' is considered ungrammatical.
Using 不然 to introduce a suggestion (e.g., '不然我们去吃饭？') is possible but less common and can sound slightly formal; 要不 is more natural for suggestions.
Writing 否者 (fǒuzhě) instead of 否则 is a common typo; 否者 is not standard.

자주 묻는 질문

When do I use 否则 vs 不然 vs 要不?: Use 否则 in formal writing and serious warnings. Use 不然 in neutral contexts—spoken or written—to mean 'otherwise'. Use 要不 in casual speech, especially to propose a suggestion or alternative. The key is formality and function: 否则 is formal, 不然 is neutral, and 要不 is colloquial.
Can 要不 and 不然 be used interchangeably?: They can both mean 'otherwise' in informal speech, but 要不 is more common for suggestions, while 不然 is neutral for consequences. For example, '要不我们去看电影？' (suggestion) sounds natural with 要不, while '不然会无聊' (otherwise it'll be boring) works better with 不然. In many contexts they overlap, but careful use of nuance improves naturalness.
Is 否则 used in everyday conversation?: Rarely. 否则 is very formal and is mostly found in official announcements, contracts, and academic writing. In daily talk, native speakers prefer 不然 or 要不. Using 否则 would sound like reading a legal document.
How do I express 'otherwise' in a conditional sentence (if...otherwise)?: In formal Chinese, you can use '如果...否则', e.g., '如果你不努力，否则就会失败' is redundant. Instead, say '如果你不努力，（那）就会失败' or simply use 否则 after the condition: '如果不努力，否则就会失败' is acceptable but 否则 alone implies the condition. In neutral or informal contexts, use '不然' after the first clause without 如果, e.g., '快点，不然我们迟到了'.