疑問詞(ぎもんし) + clause + か

How to form it

• Make the question plain, keep the question word in place with its particle, and end the question with か: 何(なに)を買(か)うか決(き)めた (I decided what to buy).
• Nouns and な-adjectives drop だ before か: どれが本物(ほんもの)か分(わ)からない (I can't tell which one is real).
• The particle after か is often left out: 誰(だれ)が来(き)たか知(し)っていますか.

Examples

Notes

• Without a clause after it, a question word + か is an indefinite word: 誰(だれ)か means "someone". See 疑問詞(ぎもんし)+か.

Common mistakes

• Using ます inside the embedded question. Say 何(なに)を買(か)うか決(き)めました, not 何(なに)を買(か)いますか決(き)めました.

Similar meaning

• 〜かどうかwhether or not

  A yes-or-no question inside a sentence: 来(く)るかどうか.

Same form, different meaning

• 疑問詞(ぎもんし)+かsomething / someone / somewhere

  誰(だれ)か, 何(なに)か: someone, something.