如果不...就...
Reach for this when you want to threaten or warn — 'if NOT X, then Y.' The conditional clause is negative ('if you don't study'), and the result clause spells out the consequence ('then you will fail'). Common in advice, ultimatums, and policy statements. The negation 不 sits inside the 如果 clause, attached to the verb or adjective you are warning about; 就 in the second clause makes the consequence sound inevitable.
Structure
如果不 [VERB / CONDITION]，(Subject) 就 [RESULT]。
rúguǒ bù... jiù...
How to Think About It
This is the negative-condition trigger. 如果 opens the hypothetical, 不 flips it to 'in the absence of,' and 就 connects to the consequence with a 'then' that feels mechanical and automatic. Native speakers hear this frame as more pointed than the plain 如果...就... — the negation makes the warning concrete: do this, OR ELSE. Drop 就 and the sentence reads as a thoughtful aside rather than a clear cause-effect.
Examples
如果不下雨，我们就去公园。
Rúguǒ bù xià yǔ, wǒmen jiù qù gōngyuán.
If it doesn't rain, we'll go to the park.
如果不早点睡，你明天就会很累。
Rúguǒ bù zǎo diǎn shuì, nǐ míngtiān jiù huì hěn lèi.
If you don't sleep early, you'll be very tired tomorrow.
如果公司不改革，就很难生存下去。
Rúguǒ gōngsī bù gǎigé, jiù hěn nán shēngcún xiàqù.
If the company doesn't reform, it will struggle to survive.
Common Mistake
Learners forget 就 in the second clause, expecting the conditional to stand alone. Chinese pairs 如果 with 就 (or 那, 那么) for cleanly marked condition-result; missing 就 makes the result feel detached.
如果不努力，你失败。
如果不努力，你就会失败。
Don't Confuse With
如果...就...
The positive-condition version (if X, then Y). 如果不...就... specifically threatens what happens in the ABSENCE of X.
除非...否则...
除非...否则... means 'unless X, otherwise Y.' Logically very close to 如果不…就…; pick 除非 for written register and when you want to emphasize the single exception.
要不然...
要不然 ('or else') is a conversational alternative that comes AFTER the recommended action (好好学习，要不然你会后悔). 如果不...就... front-loads the negative condition.
Practice
Fill in the blank: 如果不带伞，你 ___ 会被雨淋。
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就
Fill in the blank: ___ 不复习，考试就会很难。
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如果
Arrange into a sentence: 就 / 努力 / 如果不 / 进步 / 没有
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如果不努力，就没有进步。
Translate to Chinese: If we don't act now, we'll lose this opportunity.
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如果不现在行动，我们就会失去这个机会。
Write a warning using 如果不…就… about something in daily life.
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如果不戴口罩，你就有可能感冒。
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode:
Related Grammar Patterns
Acquire by listening
Hear 如果不...就... in real Chinese, not in a textbook.
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