なんで
nande[nã̠nde̞]
The Japanese phrase for "how come" is なんで (nande).
なんで is used to ask "why" or "how come".
Meaning: why (adv)
Which one should you use?
While なんで is used for "how come" in casual speech, なぜ is the more formal and standard way to ask "why". Additionally, どうして is a more polite and versatile form that is suitable for both casual and polite conversation.
Is there a formal and an informal way to say it?
なんで is informal and should be used with friends or family rather than in professional settings. For more formal situations, you can use どうしてですか？ to mean "Why is that?" or なぜなのですか？ to ask for an explanation. In informal settings, you might use どうしてなの？ to mean "Why is that?", どうしてなんだろう？ to express "I wonder why?" or なんでだろう？ to convey "how come" casually.
How does it change in a sentence?
The word なんで can be used at the beginning of a sentence to ask a question, or as an adverb within a sentence.
How do you pronounce it?
nande
Did you know?
- In certain contexts, if you use なんで incorrectly, it can sound as if you are asking 'By what means?' rather than 'Why?' For example, instead of asking why someone is late, you might accidentally ask what tool they used to arrive.
- While なんで is a common way to say 'how come', it is often viewed by Japanese speakers as quite blunt or even slightly confrontational if used with a superior. In a workplace, using it can make you sound like you are challenging their authority.
- The word なぜ is almost exclusively used in written texts, news reports and formal speeches, making it rare in spoken daily life.
Examples in context
- なんでそんなに忙しいの？How come you're so busy?This sentence is useful for asking why someone is busy.Tatoeba #3552600 by tommy_san, translation #5150077 by kemushi69
- なんでそんなにフランス語上手なの？How come you know French so well?This sentence is useful for asking why someone knows French well.Tatoeba #3556529 by tommy_san, translation #2451430 by CK
- なんでみんなそんなテンション高いの？How come everyone's so energetic?This sentence is useful for asking why everyone's energy is high.Tatoeba #3553011 by tommy_san, translation #11132356 by tsp_2
- なぜ昇進したんですか？How come you got a promotion?
- どうして約束を守らなかったんですか？How come you didn't keep your promise?
- 6 more sentences on Tatoeba
Example conversation
Two friends are talking about a sudden change in plans.
- 健太 Kentaなんで今日、学校を休むの？Nande kyou, gakkou o yasumu no?How come you are skipping school today?
- 陽葵 Himariちょっと熱があるみたいなんだ。Chotto netsu ga aru mitai nanda.I think I have a bit of a fever.
- 健太 Kenta大丈夫？無理しないでね。Daijoubu? Muri shinai de ne.Are you okay? Don't push yourself.
- 陽葵 Himariありがとう。ゆっくり休むよ。Arigatou. Yukkuri yasumu yo.Thanks. I'll take it easy.
Sources
- Pronunciation: Wiktionary entry なんで, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
