了解です

• 読み: りょうかいです
• ローマ字: ryokai desu
• 漢字の分解: 了 (complete/finish) + 解 (understand) → comprehension, understanding
• 発音: /ɾʲoː.ka.i de.sɯ/

意味

A quick 'understood' or 'roger that,' widely used in workplace and casual texting to confirm receipt of information.

了解です is a standard acknowledgment in Japanese texting and workplace chat. While 了解 alone can sound curt, adding です softens it just enough for most situations. However, there's an ongoing debate about whether 了解 is appropriate to use with superiors (some manners guides say use 承知しました instead), though in practice most people use it freely in chat apps like Slack and LINE.

例文

1. 「明日10時集合ね」「了解です！」
2. 了解です、すぐ対応します。
3. 了解です〜、ありがとうございます。

使い方ガイド

場面: texting, workplace chat, LINE, email

トーン: businesslike, efficient

正しい言い方

• 了解です、15時までに提出します (Understood, I'll submit it by 3 PM)
• 了解です！準備しておきます (Roger that! I'll get it ready)

避ける言い方

• 厳格な上司への返信では「承知しました」が無難 (For strictly hierarchical bosses, 承知しました is safer — some consider 了解 to be peer-level language)

よくある間違い

• Using 了解 without です to superiors, which sounds too blunt
• Not knowing that some Japanese business etiquette guides consider 了解 inappropriate for use with superiors

起源と歴史

了解 (ryoukai) means 'comprehension/understanding' and has been used in Japanese communication for a long time. The casual texting form 了解です became ubiquitous with the rise of workplace messaging apps. The abbreviation りょ (ryo) or り (ri) are even more casual variants.

文化的背景

時代: 2000s workplace messaging culture

世代: All ages

社会的背景: Universal

地域メモ: Used across all of Japan. The debate over 了解 vs. 承知 for superiors is well-known but not universally followed.