因为 / 所以 / 但是 — Cause, Consequence, and Contrast

为什么 (wèishénme) asks why. 因为 (yīnwèi) answers because. 所以 (suǒyǐ) links a reason to its result. 但是 (dànshì) means but, for when two statements contrast instead of agreeing.

Put 为什么 after the subject and before the verb.

Together, these four words let you ask for and give reasons, connect a cause to its consequence, and push back with a contrast — turning simple statements into real conversation.

Structure

Subject + 为什么 + Verb + Object？

你为什么喜欢茶？ Nǐ wèishénme xǐhuan chá? Why do you like tea?

因为 + Reason

因为茶很好。 Yīnwèi chá hěn hǎo. Because the tea is good.

Statement，因为 + Reason

我喝茶，因为我喜欢茶。 Wǒ hē chá, yīnwèi wǒ xǐhuan chá. I drink tea because I like tea.

因为 + Reason，所以 + Result

因为下雨，所以我不高兴。 Yīnwèi xià yǔ, suǒyǐ wǒ bù gāoxìng. Because it's raining, I'm not happy.

但是: Simple Contrast

但是 connects two statements where the second pushes back against the first — the same job as English "but".

Statement A，但是 + Statement B

我喜欢茶，但是不喜欢咖啡。 Wǒ xǐhuan chá, dànshì bù xǐhuan kāfēi. → I like tea, but I don't like coffee.

我很累，但是我要工作。 Wǒ hěn lèi, dànshì wǒ yào gōngzuò. → I'm tired, but I need to work.

Like 因为, keep the first statement complete before adding 但是 — 但是 opens the second half, it doesn't slot into the middle of the first one. (A later lesson pairs 但是 with 虽然 — "although" — for a stronger, more formal contrast; for now, a plain statement followed by 但是 is enough.)

Examples

你为什么喜欢茶？ Nǐ wèishénme xǐhuan chá?

Breakdown: 你 (you) · 为什么 (why) · 喜欢 (like) · 茶 (tea)

→ Why do you like tea?

因为茶很好。 Yīnwèi chá hěn hǎo.

Breakdown: 因为 (because) · 茶 (tea) · 很好 (is good)

→ Because the tea is good.

他为什么学习中文？ Tā wèishénme xuéxí Zhōngwén?

Breakdown: 他 (he) · 为什么 (why) · 学习 (study) · 中文 (Chinese)

→ Why does he study Chinese?

我喝茶，因为我喜欢茶。 Wǒ hē chá, yīnwèi wǒ xǐhuan chá.

Breakdown: 我 (I) · 喝 (drink) · 茶 (tea) · 因为 (because) · 我 (I) · 喜欢 (like) · 茶 (tea)

→ I drink tea because I like tea.

她为什么不喝水？ Tā wèishénme bù hē shuǐ?

Breakdown: 她 (she) · 为什么 (why) · 不 (not) · 喝 (drink) · 水 (water)

→ Why doesn't she drink water?

因为下雨，所以我不高兴。 Yīnwèi xià yǔ, suǒyǐ wǒ bù gāoxìng.

Breakdown: 因为 (because) · 下雨 (rain) · 所以 (so) · 我 (I) · 不高兴 (am not happy)

→ Because it's raining, I'm not happy.

因为我工作很忙，所以我很累。 Yīnwèi wǒ gōngzuò hěn máng, suǒyǐ wǒ hěn lèi.

Breakdown: 因为 (because) · 我工作 (my work) · 很忙 (is very busy) · 所以 (so) · 我 (I) · 很累 (am very tired)

→ Because my work is very busy, I'm tired.

我喜欢茶，但是不喜欢咖啡。 Wǒ xǐhuan chá, dànshì bù xǐhuan kāfēi.

Breakdown: 我 (I) · 喜欢 (like) · 茶 (tea) · 但是 (but) · 不喜欢 (don't like) · 咖啡 (coffee)

→ I like tea, but I don't like coffee.

我很累，但是我要工作。 Wǒ hěn lèi, dànshì wǒ yào gōngzuò.

Breakdown: 我 (I) · 很累 (am very tired) · 但是 (but) · 我 (I) · 要 (need to) · 工作 (work)

→ I'm tired, but I need to work.

Common Mistakes

Putting 为什么 at the end

- Incorrect: 你喜欢茶为什么？ (Nǐ xǐhuan chá wèishénme?) - Correct: 你为什么喜欢茶？ (Nǐ wèishénme xǐhuan chá?) — Why do you like tea?

什么 alone often sits where the answer would go (你喜欢什么？), but 为什么 always comes early — right after the subject, before the verb.

Dropping the reason clause into the middle of the main sentence

- Incorrect: 我因为喜欢茶喝茶。 (Wǒ yīnwèi xǐhuan chá hē chá.) - Correct: 我喝茶，因为我喜欢茶。 (Wǒ hē chá, yīnwèi wǒ xǐhuan chá.) — I drink tea because I like tea.

因为 introduces a whole reason clause, unlike single words such as 也/想/会 that slot in right after the subject. Keep the main statement first, then add 因为 + reason.

Dropping 但是 into the middle of the first statement

- Incorrect: 我但是喜欢茶不喜欢咖啡。 (Wǒ dànshì xǐhuan chá bù xǐhuan kāfēi.) - Correct: 我喜欢茶，但是不喜欢咖啡。 (Wǒ xǐhuan chá, dànshì bù xǐhuan kāfēi.) — I like tea, but I don't like coffee.

但是 introduces a whole contrasting clause, just like 因为 introduces a reason clause — it doesn't slot in right after the subject like 也/想/会. Keep the first statement complete, then add 但是 + the contrast.

What Can You Say Now?

You can now ask why and explain because, turning simple statements into small conversations — 你为什么不喝水？ (Why don't you drink water?), 因为我喜欢茶 (Because I like tea). You can also link a reason to its result with 因为…所以…, like 因为下雨，所以我不高兴 (Because it's raining, I'm not happy), and push back with a contrast using 但是, like 我喜欢茶，但是不喜欢咖啡 (I like tea, but I don't like coffee). Try asking someone why they like something, answering with 因为, and adding a 但是 of your own.

Quick Summary

Ask with 为什么. Answer with 因为. Link reason and result with 因为…所以…. Contrast with ，但是….