Welcome back! Today you’ll practice the very human skill of asking “Wait… why?” without sounding like a detective.
These phrases help you ask for reasons, explain your choices, and give context when plans change. Tiny grammar, big conversation power.
Level B1: In this lesson, you’ll work with natural Taiwan Mandarin phrases for asking why something happened and explaining the reason behind a decision. You’ll practice frames like 你為什麼會___？ (Nǐ wèishénme huì ___?), 那是因為___。 (Nà shì yīnwèi ___.), and 因為___，所以我___。 (Yīnwèi ___, suǒyǐ wǒ ___.) so your conversations can go beyond “what” and into “why.” Consider this your friendly reason-season lesson—Yak Yacker approves.
After this lesson you'll be able to:
Ask why someone did something using 你為什麼會___？ (Nǐ wèishénme huì ___?) and 怎麼會___？ (Zěnme huì ___?).
Ask about motivation with 你怎麼會決定要___？ (Nǐ zěnme huì juédìng yào ___?) and polite explanation requests.
Give reasons clearly with 我這麼做是因為___。 (Wǒ zhème zuò shì yīnwèi ___.) and 主要原因是___。 (Zhǔyào yuányīn shì ___.).
Connect cause and result at B1 level with 因為___，所以我___。 (Yīnwèi ___, suǒyǐ wǒ ___.).
Ready? Let's go!
When you tap play on phrases, we track your progress through this lesson.
1. Reading + Listening Practice
Hear core phrases, repeat aloud.
你為什麼會___？
Nǐ wèishénme huì ___?
Why did you ___?
Meaning: 你為什麼會___？ (Nǐ wèishénme huì ___?) means “Why did you ___?” It asks the reason behind something that happened.
When to use: Use 你為什麼會___？ (Nǐ wèishénme huì ___?) when the event already happened or is understood from context.
Tip: Don’t add 了 (le) every time. Chinese can show the past through context, so 你為什麼會遲到？ (Nǐ wèishénme huì chídào?) is already natural.
你為什麼會遲到？
Nǐ wèishénme huì chídào?
Why were you late?
你為什麼會錯過公車？
Nǐ wèishénme huì cuòguò gōngchē?
Why did you miss the bus?
你為什麼想___？
Nǐ wèishénme xiǎng ___?
Why do you want to ___?
Meaning: 你為什麼想___？ (Nǐ wèishénme xiǎng ___?) means “Why do you want to ___?”
When to use: Use 你為什麼想___？ (Nǐ wèishénme xiǎng ___?) to ask about someone’s intention, wish, or plan.
你為什麼想換工作？
Nǐ wèishénme xiǎng huàn gōngzuò?
Why do you want to change jobs?
你為什麼想學台灣華語？
Nǐ wèishénme xiǎng xué Táiwān Huáyǔ?
Why do you want to learn Taiwan Mandarin?
___的原因是什麼？
___ de yuányīn shì shénme?
What's the reason for ___?
Meaning: ___的原因是什麼？ (___ de yuányīn shì shénme?) means “What’s the reason for ___?”
When to use: Use ___的原因是什麼？ (___ de yuányīn shì shénme?) when you want a clear explanation for a situation, choice, or change.
你搬家的原因是什麼？
Nǐ bānjiā de yuányīn shì shénme?
What’s the reason you’re moving?
你取消旅行的原因是什麼？
Nǐ qǔxiāo lǚxíng de yuányīn shì shénme?
What’s the reason you canceled the trip?
怎麼會___
Zěnme huì ___?
How come ___?
Meaning: 怎麼會___？ (Zěnme huì ___?) means “How come ___?” It can sound a little surprised.
When to use: Use 怎麼會___？ (Zěnme huì ___?) when you hear something unexpected and want to know why it happened.
Tip: 怎麼會___？ (Zěnme huì ___?) can sound surprised, so use a warm tone if you don’t want it to feel like blame.
怎麼會停電
Zěnme huì tíngdiàn?
How come there’s a power outage?
怎麼會這麼晚才到？
Zěnme huì zhème wǎn cái dào?
How come you arrived so late?
我這麼做是因為___。
Wǒ zhème zuò shì yīnwèi ___.
I did it because ___.
Meaning: 我這麼做是因為___。 (Wǒ zhème zuò shì yīnwèi ___.) means “I did it because ___.”
When to use: Use 我這麼做是因為___。 (Wǒ zhème zuò shì yīnwèi ___.) when explaining your own action or decision.
我這麼做是因為我想幫忙。
Wǒ zhème zuò shì yīnwèi wǒ xiǎng bāngmáng.
I did it because I wanted to help.
我這麼做是因為時間不夠。
Wǒ zhème zuò shì yīnwèi shíjiān bú gòu.
I did it because there wasn’t enough time.
我選它是因為___。
Wǒ xuǎn tā shì yīnwèi ___.
I chose it because ___.
Meaning: 我選它是因為___。 (Wǒ xuǎn tā shì yīnwèi ___.) means “I chose it because ___.”
When to use: Use 我選它是因為___。 (Wǒ xuǎn tā shì yīnwèi ___.) when explaining why you picked one thing, option, place, or plan.
我選它是因為比較便宜。
Wǒ xuǎn tā shì yīnwèi bǐjiào piányí.
I chose it because it’s cheaper.
我選它是因為離捷運站近。
Wǒ xuǎn tā shì yīnwèi lí jiéyùnzhàn jìn.
I chose it because it’s close to the MRT station.
那是因為___。
Nà shì yīnwèi ___.
It's because ___.
Meaning: 那是因為___。 (Nà shì yīnwèi ___.) means “It’s because ___.”
When to use: Use 那是因為___。 (Nà shì yīnwèi ___.) for a simple, direct reason or background explanation.
那是因為我今天很忙。
Nà shì yīnwèi wǒ jīntiān hěn máng.
It’s because I’m very busy today.
那是因為他不太舒服。
Nà shì yīnwèi tā bú tài shūfú.
It’s because he doesn’t feel very well.
主要原因是___。
Zhǔyào yuányīn shì ___.
The main reason is ___.
Meaning: 主要原因是___。 (Zhǔyào yuányīn shì ___.) means “The main reason is ___.”
When to use: Use 主要原因是___。 (Zhǔyào yuányīn shì ___.) when there may be several reasons, but you want to point to the most important one.
主要原因是我需要休息。
Zhǔyào yuányīn shì wǒ xūyào xiūxí.
The main reason is that I need to rest.
主要原因是預算不夠。
Zhǔyào yuányīn shì yùsuàn bú gòu.
The main reason is that the budget isn’t enough.
我沒辦法，因為___。
Wǒ méi bànfǎ, yīnwèi ___.
I couldn't because ___.
Meaning: 我沒辦法，因為___。 (Wǒ méi bànfǎ, yīnwèi ___.) means “I couldn’t because ___.”
When to use: Use 我沒辦法，因為___。 (Wǒ méi bànfǎ, yīnwèi ___.) when you couldn’t do something and want to explain why.
我沒辦法去，因為我感冒了。
Wǒ méi bànfǎ qù, yīnwèi wǒ gǎnmào le.
I couldn’t go because I caught a cold.
我沒辦法幫你，因為我現在在開會。
Wǒ méi bànfǎ bāng nǐ, yīnwèi wǒ xiànzài zài kāihuì.
I can’t help you because I’m in a meeting right now.
因為___，所以我___。
Yīnwèi ___, suǒyǐ wǒ ___.
Since ___, I ___.
Meaning: 因為___，所以我___。 (Yīnwèi ___, suǒyǐ wǒ ___.) means “Since ___, I ___.”
When to use: Use 因為___，所以我___。 (Yīnwèi ___, suǒyǐ wǒ ___.) to give the reason first, then say what you did or what happened to you.
Tip: In casual speech, people may use just 因為 (yīnwèi) or just 所以 (suǒyǐ), but the full 因為___，所以我___。 (Yīnwèi ___, suǒyǐ wǒ ___.) frame is very clear for practice.
因為下雨，所以我改搭捷運。
Yīnwèi xiàyǔ, suǒyǐ wǒ gǎi dā jiéyùn.
Because it was raining, I switched to taking the MRT.
因為我不熟路，所以我查了地圖。
Yīnwèi wǒ bù shú lù, suǒyǐ wǒ chá le dìtú.
Because I didn’t know the area well, I checked the map.
你怎麼會決定要___？
Nǐ zěnme huì juédìng yào ___?
What made you decide to ___?
Meaning: 你怎麼會決定要___？ (Nǐ zěnme huì juédìng yào ___?) means “What made you decide to ___?”
When to use: Use 你怎麼會決定要___？ (Nǐ zěnme huì juédìng yào ___?) when asking about the motivation behind a decision or action.
你怎麼會決定要搬到台北？
Nǐ zěnme huì juédìng yào bān dào Táiběi?
What made you decide to move to Taipei?
你怎麼會決定要換手機？
Nǐ zěnme huì juédìng yào huàn shǒujī?
What made you decide to change phones?
你可以說明一下為什麼___嗎？
Nǐ kěyǐ shuōmíng yíxià wèishénme ___ ma?
Could you explain why ___?
Meaning: 你可以說明一下為什麼___嗎？ (Nǐ kěyǐ shuōmíng yíxià wèishénme ___ ma?) means “Could you explain why ___?”
When to use: Use 你可以說明一下為什麼___嗎？ (Nǐ kěyǐ shuōmíng yíxià wèishénme ___ ma?) when you want a polite clarification or explanation.
