かどうか means “whether or not.” It takes a yes/no question and tucks it inside a bigger sentence: 行くかどうか、まだ分かりません — “I still don’t know whether I’ll go.”
On its own, 行きますか is a direct question to someone. With かどうか, the question becomes a thing you can know, not know, ask, check or decide. It is a JLPT N4 pattern, and you will use it constantly as soon as you start talking about plans that aren’t settled yet.
かどうか turns “Is it X?” into “whether it’s X” — a question you can put inside another sentence.
What does かどうか mean?
Literally, か is the question particle and どう means “how,” so かどうか is roughly “X, or how (is it)?” — X or not. In practice, translate it as “whether (or not)” or “if” in the sense of “I don’t know if…”
- 明日晴れるかどうか分かりません。 — I don’t know whether it will be sunny tomorrow.
- 本当かどうか聞いてみます。 — I’ll ask if it’s true.
The key word is yes/no. かどうか only works when the embedded question can be answered with はい or いいえ: Will he come? Is it necessary? Did I lock the door? Questions that start with 誰, 何, いつ or どこ use a different pattern, covered below.
How to form かどうか
Put the embedded question in the plain form and add かどうか. Nouns and な-adjectives drop だ.
| Word type | Present | Past | Negative |
|---|---|---|---|
| Verb | 来るかどうか | 来たかどうか | 来ないかどうか |
| い-adjective | おいしいかどうか | おいしかったかどうか | おいしくないかどうか |
| な-adjective | 必要かどうか | 必要だったかどうか | 必要じゃないかどうか |
| Noun | 学生かどうか | 学生だったかどうか | 学生じゃないかどうか |
The whole かどうか phrase behaves like a noun, so it can take particles: 行くかどうかを決める, 行くかどうかはまだ分からない, 合格したかどうかが心配だ. In speech, the particle is often dropped and replaced with a pause or comma.
The negative column exists but is rare. Most of the time the “or not” is already built in.
When is かどうか used?
かどうか is almost always followed by a verb of knowing, asking, checking or deciding:
- Not knowing: 分からない, 知らない, 覚えていない — “I don’t know / remember whether…”
- Asking and checking: 聞く, 確認する, 調べる — “ask / check / look up whether…”
- Deciding and thinking: 決める, 考える, 迷う — “decide / think about whether…”
- Worrying: 〜かどうか心配だ — “I’m worried about whether…”
It is neutral in register. You hear it in casual talk (行くかどうか分かんない), polite speech (参加するかどうか教えてください) and written instructions (動くかどうか確認してください). For a more casual feel, speakers also use the doubled form 〜か〜ないか: 行くか行かないか分からない.
かどうか example sentences
行くかどうか、まだ分かりません。
I still don’t know whether I’ll go.
明日雨が降るかどうか、天気予報で調べます。
I’ll check the weather forecast to see if it’s going to rain tomorrow.
この書類が必要かどうか、確認してください。
Please check whether this document is needed.
鍵をかけたかどうか、覚えていません。
I can’t remember whether I locked the door.
田中さんがパーティーに来るかどうか、聞いてみます。
I’ll ask Tanaka-san if she’s coming to the party.
おいしいかどうかは、食べてみないと分かりません。
You can’t tell whether it’s good until you try it.
あの人が先生かどうか知っていますか。
Do you know whether that person is a teacher?
In each sentence you could pull the embedded part back out as a direct question — 行きますか, 雨が降りますか, 必要ですか — and answer it with yes or no. That is the test for かどうか.
Nuance of かどうか
かどうか keeps both possibilities open. The speaker is not leaning either way: 来るかどうか分からない is genuinely 50/50. If you want to lean one way, use a different pattern — かもしれない for “maybe yes,” or 来ないと思う for “probably not.”
Putting は after かどうか sets the question up as a topic and then comments on it: 合格するかどうかは、あなた次第です — “Whether you pass is up to you.” This is common in advice and explanations.
When the main verb is 知っていますか (“do you know…?”), the question becomes a polite, indirect way to ask. あの店が今日開いているかどうか知っていますか sounds gentler than asking 開いていますか straight out.
In business emails and forms you will see the same pattern in a request: ご出席いただけるかどうか、お知らせください — “Please let us know whether you can attend.” The structure is identical to the casual version; only the verbs around it become more polite. The doubled 〜か〜ないか form, by contrast, sounds more spoken and slightly more emphatic about the two options: 行くか行かないか、早く決めて — “Make up your mind — are you going or not?”
Watch the tense inside: the embedded clause keeps its own tense. 鍵をかけたかどうか asks about a past action, even if the main verb is present.
かどうか vs か
Both embed a question. Which one you use depends on whether the embedded question has a question word.
A useful shortcut: if the English uses “whether” or “if,” choose かどうか. If it uses “who,” “what,” “when” or “where,” choose plain か. Plain か can also replace かどうか in casual speech (行くか分からない), but かどうか is clearer and is what the JLPT expects. For the basics of か itself, see the question particle か.
Common mistakes with かどうか
Nouns and な-adjectives drop だ before かどうか. In the past, keep だった: 必要だったかどうか.
A question word (何時) means it isn’t a yes/no question. Use か alone.
The embedded clause uses the plain form. Politeness goes on the main verb (分かりません), not inside.
Is かどうか on the JLPT?
Yes. かどうか is standard N4 grammar. It appears in grammar blanks and sentence-ordering items, and in listening, where someone says they don’t know yet whether they can attend.
At N4 you should be able to:
- Attach かどうか to plain verbs and adjectives, and to nouns and な-adjectives without だ
- Choose かどうか for yes/no questions and か for question-word questions
- Recognise かどうか before 分かる, 知る, 聞く, 調べる and 決める
A typical distractor puts だ in front: 本当（だかどうか／かどうか）. The answer is always かどうか.
Practice questions for かどうか
Show answer
明日は休みかどうか分かりません。 — I don’t know whether tomorrow is a day off.
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このシャツはもっと大きいサイズがあるかどうか、分かりますか。 — Do you know whether this shirt comes in a bigger size?
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誰が勝つか、最後まで分からない。 — You can’t tell who’ll win until the very end.
Show answer
車を買うかどうか、まだ決めていません。 — I haven’t decided yet whether to buy a car.
Learning path for かどうか
Related grammar to review next
- か (question particle) — the particle かどうか is built on, and the one to use with question words.
- かな — “I wonder whether…” said to yourself, the sentence-final cousin of かどうか.
- かもしれない — when you lean towards “yes” instead of keeping both options open.
- てみる — the natural partner in 聞いてみる and 食べてみないと分からない.
Learn かどうか with Hane
Hane mixes かどうか and question-word か in the same drills, so you stop reaching for かどうか after 誰 and 何. Practise N4 grammar in Hane.
FAQ about かどうか
What does かどうか (ka dou ka) mean in Japanese?
かどうか (ka dou ka) means “whether or not”. It is JLPT N4 grammar. Literally, か is the question particle and どう means “how,” so かどうか is roughly “X, or how (is it)?” — X or not.
How do you form かどうか (ka dou ka)?
Put the embedded question in the plain form and add かどうか. Nouns and な-adjectives drop だ.
What is the difference between かどうか and か?
かどうか: yes/no questions. question word + か: who / what / when / where questions.
What is an example sentence with かどうか (ka dou ka)?
行くかどうか、まだ分かりません。 — I still don’t know whether I’ll go.