Ways to say it
| Vietnamese | IPA |
|---|---|
| tại sao | [taːj˧˨ʔ saːw˧˧] (Hà Nội, narrow) [taːj˨˩ʔ ʂaːw˧˧] (Huế, narrow) |
| sao | [saːw˧˧] (Hà Nội, narrow) [ʂaːw˧˧] (Huế, narrow) |
| vì sao | [vi˨˩ saːw˧˧] (Hà Nội, narrow) [vɪj˦˩ ʂaːw˧˧] (Huế, narrow) |
These words are used as interrogatives to inquire about the reason behind an action or a situation. You can place tại sao at the beginning of a sentence to ask for a reason.
What does it mean word for word?
In the phrase vì sao, the word vì means "because" or "for". In the phrase tại sao, the word tại can mean "due to" or "at".
Which one should you use?
The form tại sao is the most standard and neutral way to express why. The form sao is a shorter, more colloquial version of why, often used in spoken language. The form vì sao is used in more formal, poetic or literary contexts.
Related words
How does it change in a sentence?
In spoken Vietnamese, the word sao is frequently paired with the particle thế at the end of a sentence to express surprise or emphasis when asking why (e.g., tại sao … thế?).
Did you know?
- The word sao may be a distant relative of the Tagalog word araw, meaning 'day'. This suggests a prehistoric link between Vietnamese and Proto-Austronesian languages.
Examples in context
- tại sao bạn hỏiWhy do you ask?This sentence shows the use of sao in a question.Tatoeba #9555067 by Alex_do, translation #1368 by CK
- Sao mày xấu thế?Why are you so ugly?Tatoeba #1564368 by trieuho, translation #1406337 by marcelostockle
- Vì sao con khóc?Why are you crying?Tatoeba #4184805 by angemon, translation #36405 by CK
- Tại sao bạn đến trễ?Why are you late?
- Tại sao cô ấy không tham gia dự án này?Why is she not participating in this project?
- Sao bạn không xem bộ phim đó?Why don't you watch that movie?
- Tại sao trời lại mưa?Why is it raining?
- Bạn có lý do gì để không tham dự buổi họp này không?Do you have any reason not to attend this meeting?
- 261 more sentences on Tatoeba
Example conversation
Hương and Minh are talking about a cancelled plan.
- HươngTại sao anh không đi xem phim?Why didn't you go to the movie?
- MinhVì anh phải làm việc muộn.Because I had to work late.
- HươngTại sao anh không nói với em?Why didn't you tell me?
- MinhAnh quên mất, xin lỗi Hương.I forgot, I'm sorry Hương.
Sources
- Wiktionary, “why” translations and entries tại sao, sao, vì sao, CC BY-SA 4.0, dump of 2026-09-26.
- Word origins: Wiktionary entries sao, vì, vì sao, CC BY-SA 4.0.
- Example sentences: Tatoeba CC BY 2.0 FR.
