Translation guide
The English word 'whether' is used to introduce indirect questions or express alternatives. In Japanese, it is most commonly expressed using the particle か (ka) or the phrase かどうか (ka dou ka). The choice depends on whether the embedded question is a yes/no question or an open-ended question, and on the level of formality.
彼が来るか来ないか分かりません。
I don't know whether he will come or not.
Alternative pattern: verb + か + negative verb + か.
Expressing uncertainty about a yes/no proposition, equivalent to 'whether or not'.
Attach to the plain form of a verb, adjective, or noun + だ to embed a yes/no question. This is the most common and neutral way to say 'whether or not'.
彼が来るかどうか知っていますか。
Do you know whether he will come?
それが本当かどうか分かりません。
I don't know whether that's true.
この料理が美味しいかどうか試してみたい。
I want to try whether this dish is delicious.
Simply use the question particle か after a plain form clause. This is more common in formal or written contexts, and can sometimes sound abrupt in casual speech. Often used with verbs like 分かる, 知る, 決める.
会議がいつ始まるか教えてください。
Please tell me when the meeting starts. (lit. whether the meeting starts when)
彼が来るか分からない。
I don't know whether he'll come.
Repeat the verb/adjective in positive and negative forms to emphasize the alternatives. More explicit than かどうか.
彼が来るか来ないか分からない。
I don't know whether he will come or not.
それが正しいか正しくないか判断できない。
I can't judge whether that is correct or not.
A formal, literary equivalent of かどうか. Used primarily in written language or formal speeches.
その法案が可決されるか否かはまだ分からない。
It is still unknown whether the bill will be passed or not.
Embedding a question with a question word (who, what, where, etc.) to express 'whether' in the sense of 'I don't know who/what/where...'.
Use the question word (だれ, なに, どこ, etc.) followed by the plain form of the predicate and か. This is the standard way to embed open-ended questions.
誰が来るか分からない。
I don't know who will come. (lit. I don't know whether who will come.)
何を食べたいか決めてください。
Please decide what you want to eat.
Expressing a choice between two or more alternatives, often with 'or'.
List the alternatives with か between them. The final か is often followed by a verb like 分からない, 決める, etc.
コーヒーか紅茶か、どちらがいいですか。
Which would you like, coffee or tea? (lit. Whether coffee or tea, which is good?)
行くか行かないか、早く決めて。
Decide quickly whether you're going or not.
Expressing 'no matter whether' or 'regardless of whether', often with a concessive meaning.
Formal pattern meaning 'regardless of whether or not'. Used in written and formal spoken Japanese.
経験があるかどうかにかかわらず、応募できます。
You can apply regardless of whether you have experience or not.
Using 'whether' to introduce a clause that acts as the subject of a sentence, often with 'or not'.
Nominalize the embedded question with かどうか and mark it as the subject with が.
彼が来るかどうかが問題だ。
Whether he comes or not is the problem.
Use かどうか when the embedded question is a yes/no question (i.e., 'whether or not'). Use か alone when the embedded question contains a question word (who, what, where, etc.) or when listing alternatives. In casual speech, かどうか can be shortened to か, but this can be ambiguous.
来るかどうか分からない。
I don't know whether he'll come or not.
誰が来るか分からない。
I don't know who will come.
English often uses 'whether or not' for emphasis. In Japanese, かどうか already includes the 'or not' meaning. Adding かどうかかどうか or similar is incorrect. Use かどうか for neutral yes/no embedding, and か〜か for explicit alternatives.
明日雨が降るかどうか心配だ。
I wonder whether it will rain tomorrow.
あなたが同意するかどうかは問題ではない。
It doesn't matter whether you agree or not.
彼女は私が宿題を終えたかどうか尋ねた。
She asked whether I had finished my homework.
どこに行くかまだ決めていない。
I haven't decided where to go yet.
Rarely used, but possible when the question word is the subject of a yes/no proposition. For example, 'whether someone will come' can be rephrased as 'whether there is someone who will come'.
誰か来るかどうか分からない。
I don't know whether anyone will come.
Use それとも to explicitly mean 'or' when presenting two alternatives, especially in questions.
電車で行くか、それともバスで行くか決めてください。
Please decide whether to go by train or by bus.
Similar to にかかわらず, but slightly less formal. Means 'regardless of whether'.
天気がいいかどうかに関係なく、イベントは開催されます。
The event will be held regardless of whether the weather is good or not.
A formal, literary pattern meaning 'whether A or B'. Used with nouns or na-adjectives.
雨であれ雪であれ、試合は行われる。
Whether it's rain or snow, the game will be held.
Whether that is true or not is not important.
Using は instead of が adds a contrastive or thematic nuance.
彼が成功するかどうかは、努力次第だ。
Whether he succeeds or not depends on his effort.
行くかどうかまだ決めていない。
I haven't decided whether to go or not.
In very casual conversation, かどうか is often shortened to just か, especially with verbs like 分かる. However, this can sometimes sound blunt. To soften, add かどうか or use 〜か〜か.
来るか分かんない。
I dunno if he's coming.
行くかどうかまだ決めていない。
I haven't decided whether to go or not.
In very casual conversation, かどうか is often shortened to just か, especially with verbs like 分かる. However, this can sometimes sound blunt. To soften, add かどうか or use 〜か〜か.
来るか分かんない。
I dunno if he's coming.