疑問詞 + か: だれか / なにか / どこか | Japanese Grammar

A question word leaves a value open: 誰 asks "who?", 何 asks "what?", どこ asks "where?" — the answer is unknown, waiting to be filled in. Japanese takes that openness and freezes it. Attach the question particle か to a question word and it stops asking and starts asserting the existence of an unspecified one: だれか "someone," なにか "something," どこか "somewhere." This is the "some-" faculty of the wh-word. Its mirror image — the "no-" faculty, built with も and a negative — lives on the 疑問詞 + も〜ない page; the two are a matched pair, and this page is the first half.

The formula: question word + か

Take any question word, add か, and you get its "some-" version. The speaker knows that there is a someone, something, or somewhere — but not which one.

Question word	か	Reading	Meaning
誰 (who)	誰か	dareka	someone
何 (what)	何か	nanika	something
どこ (where)	どこか	dokoka	somewhere
いつ (when)	いつか	itsuka	sometime, someday
どれ (which)	どれか	doreka	one of them
なぜ (why)	なぜか	nazeka	for some reason, somehow

玄関に誰かいるみたい。

genkan ni dareka iru mitai

It seems like someone's at the front door.

のど渇いた。何か飲みたい。

nodo kawaita. nanika nomitai

I'm thirsty — I want to drink something.

週末、どこか行く？

shūmatsu, dokoka iku

Want to go somewhere this weekend? (casual)

いつか日本に住んでみたい。

itsuka nihon ni sunde mitai

Someday I'd like to try living in Japan.

Why か? The logic of the open value

It is not a coincidence that the question particle also builds indefinites. Both meanings come from the same core: か marks a value as unsettled. A question hands that unsettled value to the listener to resolve ("who? — you tell me"). An indefinite keeps it unsettled but still asserts that some filler exists ("who — I don't know, but someone"). So 誰か is literally "who‑(unknown)" = "someone"; 何か is "what‑(unknown)" = "something."

Once you see that, two otherwise odd words fall into place. いつか ("when‑unknown") is not "when?" but "at some unspecified time" — someday. なぜか ("why‑unknown") is not "why?" but "for some reason I can't pin down" — somehow. The same open‑value logic, applied to time and cause.

なぜか今日は集中できない。

nazeka kyō wa shūchū dekinai

For some reason I can't focus today.

この写真、どこかで見たことがある。

kono shashin, dokoka de mita koto ga aru

I've seen this photo somewhere before.

💡

Two か's can even share a sentence doing both jobs: 誰か来たの？ ("did someone come?") — the first か is the indefinite ("someone"), the sentence‑final か is the question. The particle is the same; only its position tells you which job it is doing.

Particle behaviour: を and が usually drop

When a か‑indefinite is the subject or object, the case particles が and を are normally dropped in speech. 何か食べる, not 何かを食べる; 誰か来た, not 誰かが来た. (The fuller 何かを is grammatical and used for emphasis — "eat something [specific]" — but the bare form is the default.)

何か食べようか。

nanika tabeyō ka

Shall we eat something?

誰か手伝ってくれる？

dareka tetsudatte kureru

Could someone help me? (casual)

The other particles, though, stay firmly in place. に (target), で (location), へ (direction), と (with) all attach right after the か:

困ったら誰かに相談したほうがいいよ。

komattara dareka ni sōdan shita hō ga ii yo

If you're stuck, you should talk it over with someone.

今度どこかへ遊びに行こうよ。

kondo dokoka e asobi ni ikō yo

Let's go out somewhere sometime.

💡

The pattern is clean: が/を drop, everything else survives. So it is 何か食べる (を gone) but どこかで会う (で stays), 誰か来た (が gone) but 誰かに聞く (に stays). If the particle is not が or を, keep it.

Indefinite 何か is not the question 何

The one place English speakers slip is confusing the indefinite 何か ("something") with the bare question 何 ("what"). They ask different things and expect different answers.

何食べる？

nani taberu

What are you going to eat? (I expect you to name a dish)

何か食べる？

nanika taberu

Do you want to eat something? (a yes/no offer, no dish named)

何食べる？ is a genuine wh‑question — it wants a specific answer ("ramen"). 何か食べる？ leaves the what open and really asks whether you want to eat at all. Dropping the か there turns a gentle offer into a demand to name your order.

The matched pair: か is "some-", も is "no-"

か is only one of the two faculties of a question word. Swap it for も with a negative verb and the indefinite flips to a universal negation: 誰か来た ("someone came") becomes 誰も来なかった ("no one came"). か opens one possibility; も sweeps all of them and the negative cancels them. The pair is worth learning together — the full treatment is on 疑問詞 + も〜ない, and the three‑way overview (か / も / でも) is on Question word + か / も / でも.

Common mistakes

❌ 何かを飲みたい。（普通の会話で）

Unnatural in casual speech — を is normally dropped after 何か; the bare form is the default.

✅ 何か飲みたい。

nanika nomitai

I want to drink something.

❌ 何食べる？（「何か食べる？」のつもりで）

Incorrect for an offer — bare 何 is a wh-question ('what?') and demands a named dish, not a yes/no.

✅ 何か食べる？

nanika taberu

Do you want to eat something?

❌ 誰か聞いてみる。（「誰かに聞く」のつもりで）

Incorrect — 'ask someone' needs the target particle に; dropping it reads as 'someone asks.'

✅ 誰かに聞いてみる。

dareka ni kiite miru

I'll try asking someone.

❌ 部屋に誰かいない。（「誰もいない」のつもりで）

Incorrect for 'no one' — that is the も faculty (誰も…ない); 誰か is affirmative 'someone.'

✅ 部屋に誰もいない。

heya ni daremo inai

There's no one in the room.

The last one is the great か/も confusion: か is 'some-', not 'no-'. The moment you mean "no one / nothing / nowhere," you have crossed over to the も side of the pair.

Key takeaways

Question word + か = "some-": だれか (someone), なにか (something), どこか (somewhere), いつか (someday), なぜか (somehow).
The question particle か and the indefinite か are the same word — both mark a value as unsettled; a question hands it over, an indefinite keeps it open but asserts some filler exists.
As subject/object, が and を drop (何か食べる, 誰か来た); に, で, へ, と all stay (誰かに, どこかで, どこかへ).
か is one of two faculties: か = "some-", and も + negative = "no-" — a matched pair.

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