由于/因为 (formal): due to
由于 (yóu yú) is a formal word for because or due to, used mostly in writing and at the start of a sentence. 因为 (yīn wèi) gives the same reason in everyday speech, and it is also the one you can use in the middle of a sentence.
In English
由于 and 因为 both give a reason, but they belong to different styles. 由于 is formal and mostly written, and it usually opens the sentence: 由于天气原因，航班延误了。 因为 is the everyday word and can sit at the start or in the middle. After 由于 the result often begins with 因此 or 所以, and after 因为 it usually begins with 所以.
Pick one reason word per sentence.
由于 (yóu yú) 是书面正式用语；因为 (yīn wèi) 是日常口语。
| | 由于 | 因为 |
|-|------|------|
| 语体 | 书面/正式 | 口语/日常 |
| 位置 | 常放句首 | 句首/句中均可 |
| 搭配 | 由于…因此/所以 | 因为…所以 |
| 例句 | 由于天气原因，航班延误了。 | 因为下雨，我没去。 |
结构: 由于 + 原因 + (因此/所以) + 结果
✅ 由于经济原因，公司决定裁员。(formal)
✅ 因为太累了，我没去参加聚会。(colloquial)
❌ 由于 cannot be paired with 因为 in the same sentence.
Worked examples
| Chinese | Pinyin | English | What it shows |
|---|---|---|---|
| 由于突降大雨，今天的户外活动不得不推迟。 | Yóu yú tū jiàng dà yǔ, jīn tiān de hù wài huó dòng bù dé bù tuī chí. | Due to sudden heavy rain, today's outdoor activities had to be postponed. | 由于 at sentence start + formal context (official activity) — typical written/formal pattern |
| 因为作业太多，他昨晚做到了凌晨两点才睡觉。 | Yīn wèi zuò yè tài duō, tā zuó wǎn zuò dào le líng chén liǎng diǎn cái shuì jiào. | Because there was too much homework, he worked until 2 AM before going to sleep. | 因为 — colloquial register; first-person narrative of an everyday situation |
| 由于长期缺乏运动，她的身体状况越来越差，医生建议她每天锻炼。 | Yóu yú cháng qī quē fá yùn dòng, tā de shēn tǐ zhuàng kuàng yuè lái yuè chà, yī shēng jiàn yì tā měi tiān duàn liàn. | Due to long-term lack of exercise, her health condition got worse and worse; the doctor advised her to exercise daily. | 由于 in a longer, more complex formal sentence; 越来越差 and doctor's advice give formal tone |
Word by word
Each word in this pattern on its own: what it does here, the structure, three more examples, and the mistake to avoid.
由于 (yóu yú)
A formal word for 'because of' or 'due to', most common at the start of a sentence.
Structure: 由于 + reason, (因此/所以) + result
| Chinese | Pinyin | English |
|---|---|---|
| 由于身体不舒服，他没来上课。 | Yóu yú shēn tǐ bù shū fu, tā méi lái shàng kè. | He missed class because he was unwell. |
| 由于工作太忙，我很少回家。 | Yóu yú gōng zuò tài máng, wǒ hěn shǎo huí jiā. | Because work is so busy, I seldom go home. |
| 由于交通事故，这条路堵了很久。 | Yóu yú jiāo tōng shì gù, zhè tiáo lù dǔ le hěn jiǔ. | Because of an accident, this road was blocked for a long time. |
Not: 由于因为天气不好，航班取消了。 Choose one reason word; never stack 由于 and 因为.
In the official HSK 3.0 grammar outline: level 4, conjunctions (连接分句或句子); level 4, prepositions (引出原因).
由于 is also explained in: Prepositions of Cause & Purpose: 由于, 因为, 为了 (HSK 3) · Formal vs. informal register differences (HSK 4) · Preposition 随着 (along with, as) (HSK 5).
因为 (yīn wèi)
The everyday word for 'because'; the result often opens with 所以.
Structure: 因为 + reason, (所以) + result
| Chinese | Pinyin | English |
|---|---|---|
| 因为今天是周末，路上车不多。 | Yīn wèi jīn tiān shì zhōu mò, lù shang chē bù duō. | Because it is the weekend, there are few cars. |
| 我没去，因为我感冒了。 | Wǒ méi qù, yīn wèi wǒ gǎn mào le. | I did not go because I had a cold. |
| 因为太贵了，所以我没买。 | Yīn wèi tài guì le, suǒ yǐ wǒ méi mǎi. | Because it was too expensive, I did not buy it. |
Not: 因为他病了，但是没来。 After a reason, the result is 所以 or nothing, not 但是.
In the official HSK 3.0 grammar outline: level 2, conjunctions (连接分句或者句子); level 2, prepositions (引出原因).
因为 is also explained in: Causal Sentences: 因为…所以 (HSK 2) · Prepositions of Cause & Purpose: 由于, 因为, 为了 (HSK 3).
What you need first
Every topic in GraphChinese names its own prerequisites, and these are the grammar points this one is built on. If a sentence here will not parse, one of them is why.
What this opens up
These patterns list 由于/因为 (formal) among their own prerequisites, so they become readable once this one holds.
Questions about 由于/因为 (formal)
What does 由于 (由于/因为 (formal)) mean in Chinese?
由于 (yóu yú) is a formal word for because or due to, used mostly in writing and at the start of a sentence. 因为 (yīn wèi) gives the same reason in everyday speech, and it is also the one you can use in the middle of a sentence. It is an HSK 4 grammar point.
How do you use 由于 (由于/因为 (formal)) in a sentence?
由于突降大雨，今天的户外活动不得不推迟。 — Yóu yú tū jiàng dà yǔ, jīn tiān de hù wài huó dòng bù dé bù tuī chí. — Due to sudden heavy rain, today's outdoor activities had to be postponed. 由于 at sentence start + formal context (official activity) — typical written/formal pattern.
What do you need to know before 由于 (由于/因为 (formal))?
Prepositions of Cause & Purpose (HSK 3). This pattern is built out of them, so a sentence here that will not parse usually means one of them has not landed yet.
What does 由于 (由于/因为 (formal)) lead to?
Purpose & Consequence Clauses (HSK 5). Each of them names 由于 (由于/因为 (formal)) among its own prerequisites.
Can I use 由于 in conversation?
You can, but it sounds like a news report or a formal note. For daily speech use 因为, as in 因为下雨，我没去。
Is 由于…所以… correct?
Yes, it is common and accepted, though 由于…因此… is the more formal pair. Avoid mixing 由于 and 因为 in the same sentence.
由于/因为 (formal) is one topic of 829. GraphChinese teaches them in prerequisite order, so this pattern reaches you on the day everything it rests on is proven. The whole course, HSK 0 through HSK 6, is $49 once for lifetime access.
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