Formality and informality in Japanese punctuation

In Japanese, as in any language, the context dictates the appropriate level of formality. This extends beyond vocabulary and grammar right down to the punctuation you use. While the punctuation marks themselves are the same, their application can change dramatically between a formal business document and a casual text message to a friend. Understanding this distinction is crucial for communicating your message with the right tone. This article provides a detailed comparison of formal and informal punctuation usage in Japanese.

Formality in Sentence Enders

How you end a sentence is one of the clearest indicators of formality in your writing.

Formal Usage: The Reign of the Kuten 「。」

In any formal context—such as academic essays, business correspondence, or official reports—the kuten (句点) 「。」 is the only acceptable way to end a sentence. This rule is so strict that it applies even to questions. If the sentence’s grammar already indicates a question (for example, with the particle か), a period is used instead of a question mark. Using a question mark or exclamation mark in a formal paper is generally considered unprofessional.

会議は何時から始まりますか。
かいぎはなんじからはじまりますか。
Kaigi wa nanji kara hajimarimasu ka.
What time does the meeting start?

会議        (かいぎ)            = Meeting
は                               = (topic marker particle)
何時        (なんじ)           = What time
から                          = From
始まります (はじまります) = to begin, to start
か                               = (question marker particle)

報告書を明日までに提出してください。
ほうこくしょをあしたまでにていしゅつしてください。
Hōkokusho o ashita made ni teishutsu shite kudasai.
Please submit the report by tomorrow.

報告書       (ほうこくしょ)        = Report
を                              = (object marker particle)
明日までに (あしたまでに)        = By tomorrow
提出して (ていしゅつして) = to submit

Informal Usage: Expressing Emotion with 「？」 and 「！」

In informal writing like text messages, social media posts, or emails to friends, the gimonfu (疑問符) 「？」 and kantanfu (感嘆符) 「！」 are used freely. They add a tone that mimics spoken language. Furthermore, the kuten (`。`) is often omitted entirely in short messages. It’s also common to combine marks or use them multiple times for extra emphasis.

もう着いた？
もうついた？
Mō tsuita?
Have you arrived yet?

もう                         = Already, yet
着いた (ついた)            = Arrived (past tense of 着く)

昨日のライブ、最高だった！！
きのうのライブ、さいこうだった！！
Kinō no raibu, saikō datta!!
Yesterday’s concert was the best!!

昨日      (きのう)         = Yesterday
ライブ                       = Live concert
最高      (さいこう)       = The best, supreme
だった                       = Was (casual past tense)

The Dual Nature of the Wave Dash 「〜」

Formal Usage: Indicating a Range

In formal and technical writing, the nami dasshu (波ダッシュ) 「〜」 has one primary, clear-cut function: to indicate a range between two points, like the English “from… to…”.

受付時間は月曜日〜金曜日、9時〜17時です。
うけつけじかんはげつようび〜きんようび、くじ〜じゅうしちじです。
Uketsuke jikan wa getsuyōbi–kin’yōbi, 9-ji–17-ji desu.
Reception hours are Monday to Friday, 9:00 to 17:00.

受付時間   (うけつけじかん) = Reception hours
月曜日     (げつようび)     = Monday
金曜日     (きんようび)     = Friday
9時          (くじ)               = 9 o’clock
17時        (じゅうしちじ)  = 17:00 (5 PM)

Informal Usage: Softening the Tone

In casual digital communication, the wave dash is one of the most powerful tools for adding a friendly, soft, or playful tone. It’s used to draw out the final vowel of a word, mimicking a relaxed or sing-song way of speaking. It often replaces the standard long vowel mark (ー) to add this emotional nuance.

またね〜
またね〜
Matane〜
See you later〜

またね                       = See you later (casual)
〜                              = (Adds a friendly, elongated tone)

Brackets, Parentheses, and Asides

While standard brackets (`「』`) are used similarly in both contexts, parentheses reveal a clear formal/informal split.

Formal Usage: Clarification

Formally, marukakko (丸括弧) （） are used for their standard purpose: adding supplementary information, giving readings for kanji (furigana), or citing sources.

消費税（しょうひぜい）は10パーセントです。
しょうひぜい（しょうひぜい）は１０パーセントです。
Shōhizei (shōhizei) wa 10 pāsento desu.
The consumption tax (shōhizei) is 10 percent.

消費税      (しょうひぜい)      = Consumption tax
は                               = (topic marker particle)
10パーセント                    = 10 percent

Informal Usage: Conversational Asides and Jokes

Informally, parentheses are used to inject personal asides, jokes, or actions into text, mimicking a stage whisper or a personal thought. The most famous example is `（笑）`, which is the equivalent of “lol”. It is often abbreviated to `(w)`.

今日のプレゼン、大成功だったよ（笑）
きょうのプレゼン、だいせいこうだったよ（わら）
Kyō no purezen, daiseikō datta yo (wara)
Today’s presentation was a huge success lol

今日            (きょう)            = Today
プレゼン                     = Presentation
大成功         (だいせいこう)   = Huge success
（笑）          (わら)             = lol (literally “laugh”)

Summary Table: Formal vs. Informal Punctuation