X 之所以 Y，是因为 Z
Reach for this when you want to lead with the result and then unpack the reason — 'the reason X is Y is because Z.' It's the formal, analytical cousin of 因为...所以... You'll hear it in news commentary, business explainers, and essays where the writer is making a case. Putting Y first frames it as the thing being explained; the 是因为 clause delivers the verdict.
Structure
[X] 之所以 [Y]，是因为 [Z]
... zhīsuǒyǐ ..., shì yīnwèi ...
How to Think About It
Inverted causality with a built-in spotlight. 因为...所以... is neutral ordering: cause then effect. 之所以...是因为... flips the order specifically to put the effect on stage — 'this thing you're wondering about? here's why.' The 之所以 literally means 'the reason for which' — it announces that an explanation is coming, then pays it off with 是因为.
Examples
他之所以成功，是因为他从不放弃。
Tā zhīsuǒyǐ chénggōng, shì yīnwèi tā cóng bù fàngqì.
The reason he succeeded is that he never gave up.
我之所以学中文，是因为我喜欢中国电影。
Wǒ zhīsuǒyǐ xué Zhōngwén, shì yīnwèi wǒ xǐhuan Zhōngguó diànyǐng.
The reason I'm learning Chinese is that I love Chinese films.
这家店之所以这么火，是因为价格便宜。
Zhè jiā diàn zhīsuǒyǐ zhème huǒ, shì yīnwèi jiàgé piányi.
The reason this shop is so popular is that the prices are cheap.
Common Mistake
Learners often drop 是 and write '...之所以 Y，因为 Z.' Without 是, the second clause loses its anchor and the sentence feels broken to natives. 是因为 is treated as a fixed two-character unit here — 'it IS because.'
他之所以成功，因为他很努力。
他之所以成功，是因为他很努力。
Don't Confuse With
因为...所以...
Neutral cause-first order. Use 因为...所以... for everyday explanations; switch to 之所以...是因为... when you want to spotlight the result first, essay-style.
由于...因此...
Formal but still cause-first. 由于...因此... reads like a report; 之所以...是因为... reads like an argument or analysis.
原因是...
'The reason is...' — a simpler way to deliver the cause after stating the effect. Use 原因是 when the result has already been mentioned; use 之所以...是因为... when you want to package result and reason in one sentence.
Practice
他___所以迟到，是因为路上堵车。
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之
我之所以喜欢这首歌，___因为它让我想起家。
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是
Put in order: [她 / 是因为 / 之所以 / 想 / 旅游 / 没去 / 太贵了]
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她之所以没去旅游，是因为太贵了。
Translate to Chinese: 'The reason this video went viral is that it touched a nerve.'
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这个视频之所以火，是因为它戳中了大家。
Write a sentence explaining a choice you made using 之所以...是因为...
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Example: 我之所以搬到北京，是因为工作机会更多。 (The reason I moved to Beijing is that there are more job opportunities.)
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode: