かどうかWhether or not
かどうか turns a yes-or-no question into a clause meaning “whether or not ...,” allowing that question to fit inside a larger sentence.
How the sentence works
First make the statement that could be answered yes or no. Add かどうか, then attach the larger part of the sentence that says what someone knows, checks, decides, or wonders about that issue.
The question inside a larger sentence
The clause ending in かどうか should normally be followed by something that completes the thought.
Past and negative questions
Yes-or-no questions versus missing information
Use かどうか when the issue can be answered yes or no. If the missing information is who, what, where, when, or how, keep the question word and end that clause with か instead; do not normally add どうか.
会議がどこで開かれるか確認します。
I will check where the meeting will be held.
AnalyzeThis asks for a location, not a yes-or-no answer, so the question-word clause ends with か.
One yes-or-no issue versus listed choices
かどうか packages the positive and negative possibilities as one issue: whether something is true or happens. The pattern か～か instead names two or more alternatives explicitly.
More examples
明日の試合が予定どおり行われるかどうか、朝のニュースで確認します。
I will check the morning news to see whether tomorrow's game will go ahead as scheduled.
Analyzeこの席が空いているかどうか、店員に聞いてみましょう。
Let's ask a staff member whether this seat is available.
Analyze申込書に写真が必要かどうか、案内を読んでください。
Please read the instructions to find out whether the application form requires a photograph.
Analyzeその店が日曜日も営業しているかどうか知っていますか。
Do you know whether that shop is open on Sundays too?
Analyze鍵をかけたかどうか不安になって、家に戻りました。
I became unsure whether I had locked the door, so I went back home.
Analyze旅行に行くかどうかは、今夜決めます。
I will decide tonight whether to go on the trip.
Analyze彼が本当に学生かどうかは知りません。
I do not know whether he is really a student.
Analyzeこの説明が十分かどうか、もう一度検討しましょう。
Let's consider once more whether this explanation is sufficient.
Analyze