か details
write + question marker — turns a finished sentence into a question
kaku ka
question marker — turns a finished sentence into a question
この電車は品川に止まりますか。
kono densha wa shinagawa ni tomarimasu ka.
Does this train stop at Shinagawa? neutral
弁当、持ってきたか？
bentou, motte kita ka?
Did you bring a lunch? casual
- dictionary form
- past
- negative
- negative + past
- polite
- polite + past
- polite + negative
- polite + negative + past
- na-adjective
- colloquial
- colloquial
Examples
asks a question — か marks the finished clause as one, and nothing else about the sentence moves
この電車は品川に止まりますか。
kono densha wa shinagawa ni tomarimasu ka.
Does this train stop at Shinagawa? neutral
弁当、持ってきたか？
bentou, motte kita ka?
Did you bring a lunch? casual
すみません、ここは禁煙ですか。
sumimasen, koko wa kin'en desu ka.
Excuse me, is this area non-smoking? neutral
資料はもうご覧になりましたか。
shiryou wa mou goran ni narimashita ka.
Have you had a look at the documents yet? formal
Formation
{S}かattaches to finished clause{NA-stem}かattaches to na-adjective
Variant notes
- かい — casual and male-leaning, to an intimate or a junior (元気かい？) — yes/no only, since a question word takes だい instead (誰だい, ×誰かい)
- かね — on a plain form, older-male and downward to a junior (どうかね); the same particle on です／ます is ordinary modern hedging (そうですかね)
Notes
male-leaning towards a listener, so casual speech drops it and asks with rising
intonation alone (行く？). Only the non-past だ falls away before it
(学生か, but 学生だったか), and 〜じゃないか is more often a
rhetorical "isn't it!" than a question.
Related patterns
Similar
Both close a polite question, but 〜ますか asks for the bare fact (行きますか) while 〜んですか asks after the situation behind something already in view (行くんですか) — んですか with no such context reads as prying.
でしょうか is the same question hedged — ですか asks flatly and is the everyday default, while でしょうか leaves the listener room not to know; questions upward and service speech reach for it (よろしいでしょうか).
Both close a spoken question, but か asks flatly for a fact and works in any register, while の asks after the situation behind what the speaker can see (泣いてるの？) and stays plain-style — か on a plain form is blunt where の is soft.
Lookalikes
The same particle at the other end of the sentence — sentence-final か closes the utterance, while embedded か closes a clause that always has a main verb after it acting on it (いつ終わるか知りません).
The polite negative cell of this frame IS ませんか — but as a fixed frame 一緒に行きませんか proposes joint action and is heard as an invitation by default, the literal negative question surfacing only where context blocks that (お酒は飲みませんか).
Same position, opposite move — か asks for something the speaker does not have, ね offers something the speaker already believes; 三時ですか wants the time, 三時ですね wants a nod.