理由

• Reading: りゆう
• Romaji: riyuu
• Kanji breakdown: 理 (ri) — logic, reason, principle; 由 (yuu) — cause, reason
• Pronunciation: /ɾi.jɯː/

Meaning

Reason; grounds; motive. The cause or explanation behind something.

A fundamental noun for expressing causation and explanation. Used in formal and informal contexts alike. Common patterns include 理由は～です (riyū wa ~ desu, the reason is ~) and 理由を聞く (riyū wo kiku, to ask for a reason). More neutral than 言い訳 (iiwake, excuse).

Examples

1. 遅れた理由を教えてください。 Please tell me the reason you were late.
2. 日本語を勉強する理由は何ですか。 What is your reason for studying Japanese?
3. 特に理由はありません。 There's no particular reason.

Usage Guide

Context: conversation, explanation, formal writing

Tone: neutral

Origin & History

From Chinese roots, combining 理 (logic, reason, principle) and 由 (cause, from). Together they express the logical basis or cause behind something.

Cultural Context

Era: Classical

Generation: All ages

Social background: Universal