か

The particle か is a sentence-ending particle that functions as a question marker in Japanese. It is placed at the end of a sentence to indicate that the statement is a question.

Note that Japanese doesn't change word order in questions.

• Yes/no questions

  Simply attach か to the end of a declarative sentence to turn it into a yes/no question.

  あなたはがくせい学生ですかきごう？

  Are you a student?

• Open-ended questions

  When used with question words (e.g., だれ, なん何, いつ, どこ), it forms open-ended questions.

  • 何（なに）— what

    これはなん何ですか。

    What is this?
    これはみず水です。

    This is water.

  • 誰（だれ）— who

    あのひとあの人はだれ誰ですか。

    Who is that person?
    やまだ山田さんです。

    It is Yamada.

  • いつ — when

    いつですか。

    When is it?
    あす明日です。

    It is tomorrow.

• Embedded questions

  か can also embed questions within a sentence.

  かれ彼がくる来るかしっています知っていますかきごう？

  Do you know if he is coming?

• Choice questions

  か is used between options to create choice-based questions.

  こうひいコーヒーかおちゃお茶をのみます飲みますかきごう？

  Will you drink coffee or tea?

Politeness

か is used in polite or formal speech. In casual speech, intonation alone often suffices to indicate a question, and か may be omitted.