Causal: 之所以……是因为/是由于…… (The Reason...Is Because...)
因果复句：之所以……，是因为/是由于……
Explain reasons by first stating the result, then revealing the cause using the emphatic 之所以……是因为 structure
之所以 means "the reason why." It introduces the result or phenomenon first, then 是因为 or 是由于 reveals the underlying cause. This reverses the typical Chinese cause-before-result order.
This pattern is the reverse of 因为……所以. It puts the RESULT first and the CAUSE second, creating emphasis on the reason. It says: "The reason X happened is BECAUSE Y."
Lesson Targets
Podcast
Podcast: Causal: 之所以……是因为/是由于…… (The Reason...Is Because...) (因果复句：之所以……，是因为/是由于……)
Listen to Jason & Amy explain the 因果复句：之所以……，是因为/是由于…… pattern
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Understanding 因果复句：之所以……，是因为/是由于……
Most Chinese cause-effect sentences put the cause first: 因为A，所以B. But sometimes you want to start with the result and then dramatically reveal the reason. That is what 之所以……是因为 does. 这部电影之所以好看，是因为内容丰富而有趣 (The reason this movie is good is that the content is rich and interesting). By starting with the result (the movie is good), you create curiosity — the listener wants to know WHY. Then 是因为 delivers the explanation. This pattern is powerful for argumentation, explanation, and persuasion. It is common in essays, speeches, interviews, and any context where you want to emphasize the reason behind something.
Key Points
- 之所以 (zhī suǒyǐ) = "the reason why" — introduces the result first.
- 是因为 (shì yīnwèi) = "is because" — reveals the cause.
- 是由于 (shì yóuyú) = "is due to" — more formal variant.
- This pattern reverses the normal 因为→所以 order for emphasis.
- Creates suspense: result first, then the dramatic reveal of the reason.
- Extremely useful in essays, debates, and explanatory writing.
- The subject comes before 之所以: 他之所以成功，是因为……
This pattern is a favorite in Chinese debate competitions and persuasive writing. It mirrors the rhetorical technique of presenting a thesis and then justifying it, which is highly valued in Chinese academic culture.
Key Vocabulary
Example Sentences
这部电影之所以好看，是因为内容丰富而有趣。
The reason this movie is good is that the content is rich and interesting.
妈妈之所以生气，是由于他不肯承认自己的错误。
The reason Mom was angry is that he refused to admit his mistake.
他之所以能成功，是因为他从不放弃。
The reason he could succeed is that he never gives up.
中国之所以发展这么快，是因为改革开放的政策。
The reason China has developed so quickly is the policy of reform and opening up.
我之所以选择这个专业，是因为对它有浓厚的兴趣。
The reason I chose this major is my deep interest in it.
这家餐厅之所以受欢迎，是由于菜品质量高、服务态度好。
The reason this restaurant is popular is its high food quality and good service attitude.
Common Mistakes
The subject (他) must come BEFORE 之所以, not after it. Also, 是因为 should introduce a complete clause.
Do not mix this pattern with 因为……所以. The 之所以 clause (result) comes FIRST, then 是因为 (cause).
A comma is needed between the two clauses. Also, 太累了 is more natural than repeating the subject.
Practice Exercises
Tips & Tricks
Use 之所以……是因为 when you want to create suspense: present the phenomenon, pause, then reveal the explanation.
This pattern is gold for essay introductions: start with an interesting observation, then explain why.
Remember the word order: Subject + 之所以 + Result, 是因为 + Cause. Never reverse these.
Practice by explaining everyday phenomena: 咖啡之所以提神，是因为含有咖啡因.
Homework
Write five sentences using 之所以……是因为 to explain: (1) why a person succeeded, (2) why a place is famous, (3) why a product is popular, (4) why a relationship failed, and (5) why you chose to study Chinese.