因为 ... + clause
Reach for this when someone asks why and you just want to answer with the reason — no 所以, no second half. At HSK 1, 因为 frequently stands alone: someone asks 为什么?, and you reply 因为... plus the reason. It is the shortest, most natural way to attach a cause to a question or a statement someone already made, and it sounds totally native in conversation.
Structure
因为 [REASON]
yīnwèi...
How to Think About It
Think of solo 因为 as a reply, not a sentence-builder. The 所以 clause is already living in the listener's head — they asked the question, so the result is shared context. You only need to deliver the missing half: the reason. The moment you want to state both reason AND result in one breath, you switch to the full 因为...所以... pair.
Examples
为什么不吃? 因为我不饿。
Wèishéme bù chī? Yīnwèi wǒ bù è.
Why aren't you eating? Because I'm not hungry.
我没去上课。因为我生病了。
Wǒ méi qù shàngkè. Yīnwèi wǒ shēngbìng le.
I didn't go to class. Because I was sick.
他很高兴。因为今天是他的生日。
Tā hěn gāoxìng. Yīnwèi jīntiān shì tā de shēngrì.
He's very happy. Because today is his birthday.
Common Mistake
Beginners assume 因为 must always introduce a brand-new sentence, so they pile a fresh subject on top of an obvious context. In Q&A, you drop the subject and start straight from 因为 — adding 我 in front sounds textbook, not natural.
为什么不来? 我因为我生病了。
为什么不来? 因为我生病了。
Don't Confuse With
因为...所以...
Use the full pair when you state the reason AND the result in one sentence yourself. Solo 因为 only works when the result is already in the air — usually because someone just asked why.
因为...的原因
More formal, noun-style 'for the reason of...' Use it when the reason becomes the topic of the next sentence, not when you're just answering a question.
Practice
为什么不去? ___ 我很累。
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因为
我喜欢这家店。因为东西很 ___。 (好吃 / 累)
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好吃
Put in order: [因为 / 下雨 / 了]
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因为下雨了。
Translate to Chinese: 'Why didn't he come? Because he was busy.'
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他为什么没来? 因为他很忙。
Someone asks 你为什么学中文? Reply with one short 因为 sentence.
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Example answer: 因为我喜欢中国电影。 (Because I like Chinese movies.)
Hear It in Real Episodes
This pattern appears in 3 Fluentide episodes: