なんで

• Reading: なんで
• Romaji: nande
• Kanji breakdown: 何 (nan/nani) — what; で (de) — by means of
• Pronunciation: /na.n.de/

Meaning

Why; what for; how come. A casual interrogative adverb asking for the reason behind something.

A casual alternative to どうして (doushite) and なぜ (naze). Most commonly used in informal spoken Japanese: なんで来なかったの? (Why didn't you come?). Can also express surprise or frustration: なんでそうなるの! (How does it end up like that!). The formality ladder runs: なぜ (formal) > どうして (neutral) > なんで (casual).

Examples

1. なんで昨日休んだの？ Why were you absent yesterday?
2. なんでこんなに混んでいるんだろう。 I wonder why it's so crowded.
3. なんで早く言ってくれなかったの？ Why didn't you tell me sooner?

Usage Guide

Context: conversation, friends, family

Tone: inquisitive

Origin & History

Contraction of 何で (nani de, 'by what means'), where 何 (nani) shortened to なん before the particle で. Originally asked about means ('by what?') but shifted to asking about reason ('why?').

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal