# Tại sao / vì sao / sao: why? in Vietnamese (A1)

> To ask why, put tại sao at the start of the question: Tại sao anh thích Sài Gòn? Why do you like Saigon?

Source: https://vietnamesebuddy.com/grammar/tai-sao-why/ · Updated 2026-11-10

**why?**

Pattern: `Tại sao / Vì sao / Sao + [person] + [verb]?`

Level: A1 (our estimate) · Register: everyday

Typed without accents: tai sao, vi sao, sao

To ask why, put *tại sao* at the start of the question: *Tại sao anh thích Sài Gòn?* Why do you like Saigon? It's one of the few question words that go first, as in English.

In everyday speech it's usually shortened to *sao*: *Sao hôm qua em nghỉ học?* Why weren't you in class yesterday? *Vậy* at the end makes it more conversational, usually softer, though said sharply it can sound like a complaint: *Sao em về sớm vậy?* *Vì sao* means the same and is heard more in the news and in writing.

On its own, *Sao vậy?* means "What's wrong?" or "Why's that?" (in Hà Nội, *Sao thế?*).

Answer with *vì* or, in everyday Saigon speech, *tại vì* (because); *tại* on its own often puts the blame on something: *Tại kẹt xe.* Because of the traffic (in Hà Nội, *tắc đường*). Often the answer skips the word for because: *Dạ, em bị bệnh.* I was sick.

Watch where *sao* goes. After a verb at the end, it means "how", not "why": *Anh thấy sao?* What do you think? After a negative, a final *sao* shows surprise: *Anh không biết sao?* You didn't know? To ask what something is for, use *để làm gì*.

## Examples

- Tại sao anh thích Sài Gòn? — Why do you like Saigon?
- Vì người Sài Gòn dễ thương. — Because people in Saigon are lovely.
- Sao hôm qua em nghỉ học? — Why weren't you in class yesterday?
- Saigon: Dạ, tại em bị bệnh. | Hà Nội: Dạ, tại em bị ốm. — Because I was sick.
- Saigon: Sao vậy em? | Hà Nội: Sao thế em? — What's wrong?

## Words in this pattern

- [sao](https://vietnamesebuddy.com/words/sao-why/#s_sao_why): why
- [tại sao](https://vietnamesebuddy.com/words/tai-sao/#s_tai_sao): why
- [vì sao](https://vietnamesebuddy.com/words/vi-sao/#s_vi_sao): why

## Compare

- [What for? (để) làm gì](https://vietnamesebuddy.com/grammar/de-lam-gi-what-for/): what for?
- [Why on earth? sao … lại](https://vietnamesebuddy.com/grammar/sao-lai-why-on-earth/): how come …?
- [Because: vì / tại vì / bởi vì](https://vietnamesebuddy.com/grammar/vi-because/): because (of)

Previous in Asking questions: [Whose? noun + của ai](https://vietnamesebuddy.com/grammar/cua-ai-whose/)
Next in Asking questions: [Yes/no questions with có … không](https://vietnamesebuddy.com/grammar/co-khong-question/)

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