Only if… (只有…才…)

Structure 只有 + necessary condition，才 + result

只有…才… (zhǐyǒu… cái…) marks a NECESSARY condition: ONLY if A happens does B (and no other way). 只有努力学习，才能学好 = "only by studying hard can you learn well". It’s stricter than 只要…就…: there’s no shortcut, A is essential. Note 才 (not 就) in the result.

Examples

只zhǐ有yǒu努nǔ力lì学xué习xí，才cái能néng学xué好hǎo。
Only by studying hard can you learn well.
只zhǐ有yǒu他tā才cái知zhī道dào。
Only he knows.
只zhǐ有yǒu多duō练liàn习xí，才cái能néng进jìn步bù。
Only by practising a lot can you improve.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.