か・
A question can sit inside a longer sentence: "I know where he lives", "I don't know if he's coming". With a question word it ends in か. A yes-or-no question normally ends in かどうか.
with a question word
I know where Mr. Tanaka lives.
yes or no
I still don't know whether Mr. Tanaka is coming to the meeting.
With a question word
Question word … plain form + か
何を食べたか, だれが来るか, いつ行くか.
Yes or no
Plain form + かどうか
行くかどうか, 行ったかどうか, おいしいかどうか. Plain か is also said: 行くか分からない.
Noun, な-adjective
Noun／な-adjective + か／かどうか
The だ is usually left out: 学生かどうか, 静かかどうか, 出口がどこか.
After it
知っている・分かる・聞く・決める…
Mostly a verb of knowing, asking, telling, deciding or checking. Also 覚えている, 忘れる, 教える, 調べる.
With a question word: か
English changes the word order: "Where does he live?" becomes "where he lives". Japanese moves nothing. The question keeps its か, and the rest of the sentence follows.
What time does the next bus leave?
Asking straight out.
Do you know what time the next bus leaves?
The same question inside another. 出ます is now 出る.
The question inside is plain. The politeness comes once, at the end of the sentence.
Not said: 次の
(Do you know what time the next bus leaves?)
I don't remember what I ordered.
The teacher knows who painted this picture.
We decided where to hold the next meeting.
English says "where to hold". Japanese uses the plain verb here too.
Yes or no: かどうか
With no question word, the usual ending is かどうか: "whether".
Let's ask a staff member whether this seat is available.
I started to worry about whether I had locked the door, so I went back home.
I don't know whether he is really a student.
A noun goes straight before it, with no だ. The は makes the question the topic.
English often says "if" here: "I don't know if I can go." That isn't the "if" of a condition, so it is かどうか and not たら.
I don't know yet if I can go tomorrow.
Not said: 明日行けたら、
(I don't know yet if I can go tomorrow.)
か or かどうか?
I will check what time the next train comes.
何時 is a question word. The answer is a time.
I will check whether the next train will be delayed.
No question word. The answer is yes or no.
A question word and かどうか don't go together.
Not said: 次の
(I will check what time the next train comes.)
For a yes-or-no question you will also meet plain か.
I don't know whether he's coming.
Says outright that the answer is yes or no.
I don't know if he's coming.
Shorter. It means the same.
Three to learn whole
〜か知っていますかdo you know…?
Do you know what time the meeting starts?
〜か分かりませんI don't know…
I don't know what to do.
〜か教えてくださいplease tell me…
Please let me know what time you'll arrive.
Close neighbours
At the end of a sentence, か puts a question to someone. Between two choices it is "or", and inside a sentence each choice takes its own か.
I have not decided yet whether to go by train or by bus.
何か・だれかN5
As single words these are "something" and "someone", and nothing is being asked. だれか来た is "someone came"; だれが来たか is "who came".
Let's eat something.
Check yourself
1Which one fits?
山田さんが
Choose an answer to see why.
2"I don't know what time the shop opens."
Choose an answer to see why.
3"I don't know yet if I'll buy it."
Choose an answer to see why.
More detail
Particles after it
が and を are usually left out after the か. は stays: "as for whether…".
I will decide tonight whether to go on the trip.
行くか行かないか
Saying both halves means the same as 行くかどうか.
Please decide by tomorrow whether you're going or not.
More sentences
I asked at reception what time the bus leaves.
I can't remember where I put the key.
The team has not yet decided which proposal to choose.
The police are investigating where the accident occurred.
Do you know whether that shop is open on Sundays too?
I asked the station employee whether the train had already left.
Please check that the schedule hasn't changed.