之所以……是因为……
Reach for this when you want to flip the usual order of cause and effect — name the result first, then explain why. It's the analyst's tool: 'The reason X happened is because Y.' Where 因为...所以... starts with the cause and arrives at the result, 之所以...是因为... starts with the result the listener is already curious about, then reveals the cause as the punchline. You'll see it constantly in op-eds, post-game analysis, product explanations, and any sentence framed as 'here's what's really going on behind this.'
Structure
[SUBJECT] 之所以 [RESULT]，是因为 [CAUSE]
zhī suǒ yǐ... shì yīnwèi...
How to Think About It
Mirror-image of 因为...所以...: result first, cause second. The subject lives BEFORE 之所以, not between 之所以 and the verb. Think of 之所以 as a literary way of saying 'the reason it [verb-ed]...' — it grabs the verb phrase that follows and turns the whole thing into a noun-like topic, and 是因为 then introduces the answer. Because 之所以 leans formal, you'll meet it more in writing and news scripts than in chitchat.
Examples
他之所以迟到，是因为路上堵车了。
Tā zhī suǒ yǐ chídào, shì yīnwèi lùshang dǔchē le.
The reason he was late is that there was traffic on the road.
我之所以选择这份工作，是因为我喜欢这里的同事。
Wǒ zhī suǒ yǐ xuǎnzé zhè fèn gōngzuò, shì yīnwèi wǒ xǐhuan zhèlǐ de tóngshì.
The reason I chose this job is that I like the colleagues here.
这部电影之所以受欢迎，是因为它讲了一个真实的故事。
Zhè bù diànyǐng zhī suǒ yǐ shòu huānyíng, shì yīnwèi tā jiǎng le yí ge zhēnshí de gùshi.
The reason this movie is popular is that it tells a true story.
Common Mistake
Learners place the subject inside 之所以 (writing 之所以他...) the way English puts the subject after 'the reason why.' In Chinese the subject stays in front of 之所以, like a topic that's already on the table.
之所以他成功，是因为他很努力。
他之所以成功，是因为他很努力。
Don't Confuse With
因为...所以...
Use this when you start from the cause and walk forward to the result. 之所以...是因为... starts from the result and walks backward to the cause.
由于...因此...
Use this formal cause-first connector in essays and reports; 之所以...是因为... is also formal but specifically inverts the order.
...的原因是...
Plain noun-phrase version ('the reason for X is Y'). 之所以...是因为... feels more rhetorical and sets up a stronger explanatory beat.
Practice
Fill in the blank: 他之所以学中文，___ 因为他想去中国工作。
Show answer
是
Fill in the blank: 我 ___ 不去，是因为我太累了。
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之所以
Arrange: 之所以 / 她 / 成功 / 是因为 / 她 / 不放弃
Show answer
她之所以成功，是因为她不放弃。
Translate: The reason prices went up is that demand became greater.
Show answer
价格之所以上涨，是因为需求变大了。
Write one sentence explaining why you started learning Chinese using 之所以…是因为…
Show answer
我之所以开始学中文，是因为我对中国文化很感兴趣。
Hear It in Real Episodes
This pattern appears in 4 Fluentide episodes: