因为...所以... (yīn wèi... suǒ yǐ...) for Cause and Effect
Reach for this when you want to explicitly link a reason to its result — 'because X, so Y.' It's the workhorse cause-and-effect connector in Chinese: 因为 introduces the reason, 所以 introduces the result. Use it for everyday explanations — why you're late, why something costs more, why someone didn't show up. You'll meet it within the first weeks of study and use it for the rest of your Chinese-speaking life.
Structure
因为 [REASON], 所以 [RESULT]
yīnwèi... suǒyǐ...
How to Think About It
Chinese keeps BOTH halves. In English you pick one — 'I was tired, SO I left' or 'BECAUSE I was tired, I left.' Chinese says both: 因为我累了, 所以我走了. Native ears feel a sentence with only 因为 (no 所以) as hanging in the air — the result isn't sealed. Treat 因为...所以... as a single grammatical unit, not two interchangeable parts.
Examples
因为下雨, 所以我没去公园。
Yīnwèi xiàyǔ, suǒyǐ wǒ méi qù gōngyuán.
Because it rained, I didn't go to the park.
因为他很忙, 所以没来。
Yīnwèi tā hěn máng, suǒyǐ méi lái.
Because he was busy, he didn't come.
因为太冷了, 所以我穿了两件毛衣。
Yīnwèi tài lěng le, suǒyǐ wǒ chuān le liǎng jiàn máoyī.
Because it was too cold, I put on two sweaters.
Common Mistake
English speakers drop 所以 because doubling 'because' and 'so' sounds redundant in English. In casual Chinese you sometimes can, but at HSK 1-3, always keep both — your sentence will sound complete and well-formed.
因为不要钱, 用的人多。
因为不要钱, 所以用的人多。
Don't Confuse With
由于...因此...
Same meaning, formal register. Use 由于...因此... in essays, news, and reports; use 因为...所以... in speech and casual writing.
之所以...是因为...
Flips the order — result first, reason second ('The reason X is because Y'). Use it for emphasis on the cause: '我之所以学中文, 是因为我喜欢中国电影.'
既然...就...
Looks similar but means 'since/given that' — the reason is treated as already established, then you suggest a logical consequence: '既然下雨了, 就别去了.' Less neutral, more concluding.
Practice
___ 我饿了, 所以我吃了一个苹果。
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因为
因为他生病了, ___ 没来上课。
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所以
Put in order: [所以 / 因为 / 我 / 喜欢 / 它 / 买了]
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因为我喜欢它, 所以买了。
Translate to Chinese: 'Because she likes coffee, she bought a cup.'
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因为她喜欢咖啡, 所以她买了一杯。
Write one sentence using 因为...所以... about why you started learning Chinese.
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Example answer: 因为我想去中国旅游, 所以我开始学中文。 (Because I want to travel to China, I started learning Chinese.)
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode:
Related Grammar Patterns
Acquire by listening
Hear 因为...所以... (yīn wèi... suǒ yǐ...) for Cause and Effect in real Chinese, not in a textbook.
Fluentide picks the next news episode at your level, so this pattern shows up again and again in real context. The transcript marks it, the audio drills it. Free to start, no card.