Why Japanese Questions Can End with 。 Instead of ？

Many beginners open their first textbook and stop at the first question: 今日は何曜日ですか。 It is clearly a question, so why does it end with a full stop and not a question mark? The short answer is that Japanese does not need the mark, because the particle か already says it is a question. The longer answer explains when you will see 。, when you will see ？ and which one to use yourself.

The learner's question

A typical thought goes like this: wouldn't 今日は何曜日ですか。 use a question mark? In English, the mark at the end is how the reader knows to hear a question. In Japanese polite speech the job is done earlier, inside the sentence, so the punctuation at the end has less to do.

How か marks a question

か (ka) is a sentence-final particle, a small word at the end of a sentence that adds a meaning to the whole sentence. When か comes at the end of a polite sentence, it turns a statement into a question. No question word is needed, and no change in word order.

• 学校に行きます。 (がっこうにいきます, gakkō ni ikimasu) means I am going to school (or: I go to school).
• 学校に行きますか。 (がっこうにいきますか, gakkō ni ikimasu ka) means Are you going to school?
• 今日は何曜日ですか。 (きょうはなんようびですか, kyō wa nan'yōbi desu ka) means What day of the week is it today?

Why textbooks and formal writing use 。

The full stop 。 is called 句点 (くてん, kuten). Because か has already marked the question, textbooks, exams and most formal writing simply close a polite question with 。, the same mark as for any other sentence. Written this way, 今日は何曜日ですか。 is not a mistake and not a statement in disguise; it is the standard form.

Traditional Japanese writing had no question mark. ？ came into Japanese writing from Western languages, and in formal writing it is usually left out, and in casual writing it is common. We tried to read the official Japanese guidance on this today and could not confirm what it says about ？, so we describe the general habit and do not quote a rule. What you can rely on is what you see in your own materials: textbooks and exams follow the か plus 。 pattern.

Side by side

• 今日は何曜日ですか。 (きょうはなんようびですか, kyō wa nan'yōbi desu ka): the formal and textbook form.
• 今日は何曜日ですか？ (きょうはなんようびですか, kyō wa nan'yōbi desu ka): the same sentence in a friendlier, more casual style. Both mean What day of the week is it today?

Where ？ is common

You will see ？ often in text messages, chat apps, manga, adverts, social media and other casual or lively writing. It is normally the full-width ？, which has the same width as a Japanese character, and it is usually followed by nothing or by a space. It adds a softer, more spoken feeling, a bit like a rising voice.

Casual questions without か

In casual speech, Japanese speakers often drop か and ask the question with rising intonation alone. A voice can rise, but a page cannot, so in writing these questions normally need ？ to show that they are questions.

• 行く？ (いく, iku) means Are you going?
• 元気？ (げんき, genki) means How are you? or Are you well?
• これ、何？ (これなに, kore nani) means What is this?

Examples compared

The last row is not a question at all. It is a statement that contains a question, called an embedded question: 何時 (what time) plus か sits inside the sentence, and the whole sentence means I do not know. So it ends with 。 like any statement. What decides the mark is the whole sentence: 何時か分かる？ (Do you know what time it is?) is a casual question, so it takes ？.

What to do in practice

• Exams and homework: follow your textbook. Write 。 after か.
• Messages and chat: ？ is fine, and so is 。 or nothing. Choose the tone you want.
• Casual questions without か: use ？, so the reader knows it is a question.
• Never put 。 after ？ (or after ?). Do not stack 。 with another mark.

Common mistakes

• Mixing the half-width ? into Japanese text. Careful writing uses the full-width ？, which matches the width of the surrounding characters; half-width looks out of place, though you will see it in casual chat.
• Adding ？ after か in formal writing, an exam or a letter, where 。 is expected.
• Forgetting か in polite questions, so 学校に行きます？ sounds more casual and spoken; in a textbook or exam answer keep か.
• Putting ？ at the end of a statement that only contains an embedded question, such as 何時か分かりません？, which turns a statement into something odd.

To see how か works with other sentence endings, browse the grammar section and practice in the lessons.

Punctuation can be tricky to type too, so read our post on how to type Japanese without a Japanese keyboard. For another symbol that looks odd to newcomers, see what the ※ reference mark means.

If か is a hiragana you still need to recognise quickly, read hiragana vs katakana: what is the difference.

Words from this post

Official information

On 21 October 2026 we opened the Agency for Cultural Affairs press release about its council's 2022 recommendation on writing official documents. It confirms that the recommendation was submitted on 7 January 2022 and is meant to replace a 1951 guide for government writing. The page does not mention question marks, and we could not read the full text, so we cite nothing about ？ from it.