当...的时候，说明...
Reach for this when you want to interpret a phenomenon — 'when X is happening, it tells us Y.' It's the analyst's pattern, the move op-ed writers and commentators use to turn an observation into a verdict. The first half describes a moment or trend, the second half delivers what that moment means. Useful for essays, social commentary, and any time you're connecting evidence to conclusion.
Structure
当 [SITUATION] 的时候，说明 [CONCLUSION]
dāng... de shíhòu, shuōmíng...
How to Think About It
当...的时候 sets up an observed moment, then 说明 acts as the analytical hinge — 'this fact means / proves / shows.' Unlike 因为...所以... (which states cause→effect), this pattern reads evidence to surface a hidden truth. Native ears hear it as more thoughtful and editorial: you're not arguing causality, you're decoding meaning. Drop 说明 and you lose the interpretive move.
Examples
当年轻人不愿意结婚的时候, 说明社会的压力太大了。
Dāng niánqīng rén bù yuànyì jiéhūn de shíhòu, shuōmíng shèhuì de yālì tài dà le.
When young people don't want to get married, it shows that social pressure is too high.
当一个产品卖不出去的时候, 说明定价有问题。
Dāng yí gè chǎnpǐn mài bù chūqù de shíhòu, shuōmíng dìngjià yǒu wèntí.
When a product doesn't sell, it shows the pricing has a problem.
当孩子不愿意说话的时候, 说明他在害怕。
Dāng háizi bù yuànyì shuōhuà de shíhòu, shuōmíng tā zài hàipà.
When a child won't speak, it shows he's afraid.
Common Mistake
Learners use 是 instead of 说明 ('当...的时候，是...问题'), but 说明 is the analytical verb here — 'shows / proves / indicates.' Replacing it with 是 turns the sentence into a flat equation and loses the diagnostic feel.
当大家都不信任政府的时候, 是制度有问题。
当大家都不信任政府的时候, 说明制度有问题。
Don't Confuse With
因为...所以...
States cause and effect directly. Use 因为...所以... when you can name the cause; use 当...的时候，说明... when you're inferring meaning from an observed pattern.
如果...就...
Conditional 'if X then Y' — hypothetical. 当...的时候，说明... is for a situation that's actually happening and what it reveals.
...，这意味着...
Almost the same meaning — 'this means.' 意味着 is a bit more formal and writerly; 说明 sounds more like spoken analysis. Both work in essays.
Practice
___ 大家都很安静的时候, 说明有问题。
Show answer
当
当价格一直在涨的时候, ___ 需求很大。
Show answer
说明
Put in order: [说明 / 当 / 的时候 / 累了 / 他 / 不说话]
Show answer
当他不说话的时候, 说明累了。
Translate to Chinese: 'When everyone stays silent, it shows there's a problem.'
Show answer
当大家都不说话的时候, 说明有问题。
Write one sentence using 当...的时候，说明... to interpret a social phenomenon.
Show answer
Example answer: 当越来越多的人选择不生孩子的时候, 说明生活成本太高了。 (When more and more people choose not to have kids, it shows the cost of living is too high.)
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode: