HSK 7
之所以⋯⋯，是因为/是由于⋯⋯
zhī suǒ yǐ ⋯ ⋯ ， shì yīn wèi / shì yóu yú ⋯ ⋯
之所以⋯⋯，是因为/是由于⋯⋯ (The reason… is because…)
Explanation
之所以⋯是因为/是由于⋯ is a cause-effect construction in a compound sentence (a multi-clause sentence), special in that it states the RESULT first and only then states the CAUSE, meaning 'the reason ... is because ...'.
(subject) + 之所以 (zhīsuǒyǐ) + result, 是因为 (shì yīnwèi) / 是由于 (shì yóuyú) + cause.
电影之所以好看，是因为内容有趣.
when you want to foreground the result to draw attention, and only then explain the cause; it has a formal flavor, often seen in written and argumentative texts. More formal than the ordinary 因为...所以... pattern.
因为...所以... (yīnwèi...suǒyǐ...) states the cause first; whereas 之所以...是因为... reverses this, stating the result first — the two have opposite word order.
mistakenly using 所以 after 之所以 (wrong: 之所以好看，所以内容有趣) — after 之所以 it must be 是因为/是由于; and placing 之所以 in the cause clause instead of the result clause.
Examples
The reason this film is enjoyable is that its content is very interesting.
The reason Mom got angry is that he refused to admit his own mistake.
Practice
Test your understanding with a quick quiz
Learn “之所以⋯⋯，是因为/是由于⋯⋯” effectively
The grammar point “之所以⋯⋯，是因为/是由于⋯⋯” (之所以⋯⋯，是因为/是由于⋯⋯ (The reason… is because…)) is one of the key structures at HSK 7. To use it fluently, you need to understand the contexts where it's used and practice regularly.
Study tip: read the examples aloud many times to build a natural reflex. Then try making your own sentences for your own situations. Use the audio button to hear and practice accurate pronunciation.
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