Ways to say it
| Japanese | Romanization (Wiktionary) | IPA |
|---|---|---|
| 了解 | ryōkai | [ɾʲo̞ːka̠i] (narrow) |
| ラジャー | rajā | [ɾa̠ʑa̠ː] (narrow) |
了解 is used to indicate that you have received or understood information. It is a common way to acknowledge a request or a piece of information, particularly in digital communication like messaging apps. You may also see the related term ロジャー used as a male given name.
What does it mean word for word?
The word 了解 is composed of characters meaning 'understanding' and 'agreement/clarification'.
Which one should you use?
While 了解 is a standard way to say 'understood' or 'roger' in casual or semi-formal settings, ラジャー is a katakana transliteration of the English word used as slang or in a playful, military-style manner, often seen in anime or pop culture.
Is there a formal and an informal way to say it?
了解 is suitable for casual or semi-formal settings, but it is not polite enough to use with a superior or a customer. In formal situations, you should use 承知 (shōchi) to indicate that you have understood or acknowledged something.
Related words
How do you pronounce it?
ryōkai
Did you know?
- In fast-paced digital chat, 了解 is often shortened to the single character り (ri), which functions as a slangy 'k' or 'got it' among teenagers.
- In Japanese military and aviation contexts, the actual phrase used for 'roger' is 了解 (ryōkai), but the English loanword ラジャー (rajā) is almost exclusively reserved for fictional media like anime and movies.
- In many professional-grade instant messaging apps used in Japan, users often simply type the single character 了 as a shorthand for 'roger' or 'understood'.
Examples in context
- 了解。Roger that.This example shows how to use 了解 to say 'Roger that.'Tatoeba #762125 by arihato, translation #1453426 by Spamster
- 了解！Roger!Tatoeba #1165060 by emmettricks, translation #1165072 by mookeee
- 了解しました。ryōkai shimashita.Received.
- 2 more sentences on Tatoeba
Example conversation
Two colleagues are coordinating a meeting time.
- 結衣 Yui明日の会議は十時からでお願いします。Ashita no kaigi wa jū-ji kara de onegaishimasu.Please make tomorrow's meeting start at ten.
- 大翔 Hiroto了解。カレンダーに入れておくよ。Ryōkai. Karendā ni irete oku yo.Roger. I'll put it in my calendar.
- 結衣 Yuiありがとうございます。Arigatō gozaimasu.Thank you very much.
- 大翔 Hirotoいいえ、気にしないで。Iie, ki ni shinaide.No problem, don't worry about it.
Sources
- Wiktionary, “roger” translations and entries 了解, ラジャー, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
