Meaning & Usage
✨ Basic Meaning
“Whether or not,” “if.”
🎯 Primary Function
To turn a yes/no question into a noun clause that serves as the object or subject of the main verb in the sentence, expressing uncertainty or asking for verification.
📋 Grammar Structure
Plain Form (e.g., 食べる, 食べた) + かどうか
Plain Form (e.g., 寒い) + かどうか
Plain Form (e.g., 好きだ) + かどうか (The ‘だ’ is often dropped, but using the full plain form is safe.)
Plain Negative Form (e.g., 食べない) + かどうか
🎭 Usage Contexts
Formal Situations
Commonly used. The formality is conveyed by the main verb (e.g., 検討いたします).
Informal Situations
Very common and natural.
Written Language
Commonly used in reports, essays, and formal correspondence to state facts under investigation or uncertainty.
Spoken Language
Highly frequent, especially when expressing personal uncertainty.
💡 Common Applications
Reporting Uncertainty
Used after verbs like わかる (to know), 知る (to know), or 疑問に思う (to doubt) to express a lack of certainty about the preceding clause.
Example: 彼が来るかどうか、わかりません。(I don’t know whether he will come.)
Seeking Confirmation/Checking
Used with verbs like 確認する (to confirm), 尋ねる (to ask), or 調べる (to investigate) when requesting verification of a fact.
Example: 答えが正しいかどうか、確認してください。(Please check whether the answer is correct.)
Expressing a Decision Point
Used with verbs like 決める (to decide), 検討する (to consider), or 議論する (to discuss) to frame the subject of a pending resolution.
Example: 行くかどうか、まだ決めていません。(I haven’t decided whether to go or not.)
Frequency
High (Very common in both spoken and written Japanese)
Difficulty
JLPT N4/N3
Tag:
Example Sentences
Example #1
新しいスマホを買うかどうか、まだ決めていません。
Furigana: あたらしぃ スマホを かう かどうか、まだ きめて いません。
Romaji: Atarashii sumaho o kau ka dou ka, mada kimete imasen.
English: I haven’t decided whether to buy the new smartphone or not.
Example #2
ドアが閉まっているかどうか、確認してください。
Furigana: ドアが しまって いる かどうか、かくにん して ください。
Romaji: Doa ga shimatte iru ka dou ka, kakunin shite kudasai.
English: Please check whether the door is locked or not.
Example #3
明日の天気がいいかどうか、わかりません。
Furigana: あしたの てんきが いい かどうか、わかりません。
Romaji: Ashita no tenki ga ii ka dou ka, wakarimasen.
English: I don’t know whether tomorrow’s weather will be good or not.
Example #4
一番重要なのは、材料が新鮮かどうかだ。
Furigana: いちばん じゅうようなのは、ざいりょうが しんせん か どうか だ。
Romaji: Ichiban jūyō na no wa, zairyō ga shinsen ka dou ka da.
English: The most important point is whether the ingredients are fresh or not.
Example #5
先生は生徒に答えが正しいかどうか尋ねた。
Furigana: せんせいは せいと に こたえが ただしい か どうか たずねた。
Romaji: Sensei wa seito ni kotae ga tadashii ka dou ka tazuneta.
English: The teacher asked the student whether the answer was correct or not.
Example #6
彼が留学生かどうか疑問に思う。
Furigana: かれが りゅうがくせい か どうか ぎもん に おもう。
Romaji: Kare ga ryūgakusei ka dou ka gimon ni omou.
English: I wonder whether he is a foreign exchange student or not.
Example #7
彼女は試験に合格したかどうか心配している。
Furigana: かのじょは しけん に ごうかく した か どうか しんぱい して いる。
Romaji: Kanojo wa shiken ni gōkaku shita ka dou ka shinpai shite iru.
English: She is worried about whether she passed the exam or not.
Example #8
あの提案が現実的かどうか、議論しましょう。
Furigana: あの ていあん が げんじつてき か どうか、ぎろん しましょう。
Romaji: Ano teian ga genjitsuteki ka dou ka, giron shimashō.
English: We will discuss whether that proposal is realistic or not.
Example #9
この電車が渋谷に行くかどうか、知りたいです。
Furigana: この でんしゃ が しぶや に いく か どうか、しりたい です。
Romaji: Kono densha ga Shibuya ni iku ka dou ka, shiritai desu.
English: I want to know if this train goes to Shibuya or not.
Example #10
新しい社員がその仕事に適しているかどうか判断する必要がある。
Furigana: あたらしい しゃいんが その しごと に てきして いる か どうか はんだん する ひつよう が ある。
Romaji: Atarashii shain ga sono shigoto ni tekishite iru ka dou ka handan suru hitsuyō ga aru.
English: They need to judge whether the new employee is suitable for the job or not.
Notes & Nuances
📌 Important Points
Use ‘だ’ for Nouns and Na-adjectives.
When using a noun or a na-adjective (like 暇), the linking particle だ (plain form of です) must be used before かどうか. (e.g., 先生だ + かどうか).
Example: 彼が先生かどうか、知りたい。(I want to know whether he is a teacher or not.)
The entire structure functions as a noun clause.
The entire clause [Verb/Adj + かどうか] acts as a noun phrase and often functions as the subject or object of the main sentence.
Example: 新しい方法がうまくいくかどうか、みんなで考えましょう。(Let’s all think about whether the new method will work or not.)
It is a more explicit way to express a yes/no uncertainty than just using ‘か’.
While かどうか explicitly includes the ‘or not’ (どうか), you can also simply use the particle か when the uncertainty is clear from context, but かどうか is more emphatic. The use of ‘どうか’ literally means ‘how/what way’, reinforcing the uncertainty.
Example: 彼が行くか行かないか、確認して。(Check if he is going or not.)
⚠️ Common Mistakes
❌ 彼は学生だかどうか知りたい。
✅ 新しい かどうか -> 新しいかどうか
Students sometimes mistakenly use ‘na’ before かどうか with Na-adjectives (like 好き). The correct structure is the plain form (好きだ, or often just 好き) immediately followed by かどうか.
❌ I don’t know if he will come or not. (Over-literal translation)
✅ …whether or no/n’t…
In English, “whether” already implies the “or not.” While “whether or not” is common, learners should use natural English when translating, and understand that in Japanese, かどうか is the explicit phrasing for the binary choice.
❌ 彼が来ますかどうか、わかりません。
✅ 必ずプレーンフォーム (Plain Form) を使う。
A common error is using the polite form (ます/です) before かどうか. This grammar rule strictly requires the Plain Form (dictionary form, ta-form, nai-form, etc.) for the clause preceding かどうか.
🏛️ Cultural Context
Politeness Level: Neutral. The overall politeness of the sentence is determined by the main verb (e.g., わかりません [polite] vs. わからない [plain]).
Social Situations: Suitable for all social situations, from business meetings (when checking facts) to casual conversations (when expressing uncertainty).
Regional Variations: Standard across all regions.
🔍 Subtle Differences
~か vs. ~かどうか
~か simply embeds a question (e.g., 彼は来るか知りたい). ~かどうか explicitly presents a binary choice (yes/no) and emphasizes the uncertainty surrounding that choice.
When to use: Use ~かどうか when the uncertainty is the main focus or when you want to be clear about the “yes or no” nature of the question. Use ~か when the uncertainty is secondary or for a more concise expression.
~かどうか vs. ~もし[Verb/Adj]なら (Moshi… nara)
~かどうか embeds a question or uncertainty. もし～なら is used for a conditional hypothesis (if X is the case, then Y).
When to use: Use ~かどうか when you are seeking or expressing knowledge/decision about a fact. Use もし～なら when describing an action to be taken contingent on a hypothetical state.
📝 Conjugation Notes
The clause preceding かどうか must be in the Plain Form (常体 – jōtai). This includes: * Verbs: Dictionary form, Ta form, Nai form. * I-adjectives: Plain form. * Na-adjectives: Plain form (e.g., 暇だ, Genki da). The ‘だ’ can sometimes be omitted, especially in conversation or before a following verb. * Nouns: Plain form (e.g., 学生だ). The ‘だ’ is essential for Nouns.
🔊 Pronunciation Tips
The particle か and どうか should be pronounced clearly, with a slight pause or break between the preceding word’s plain form and かどうか. There is usually no strong inflection on the ‘かどうか’ itself.
🧠 Memory Tips
Think of か (ka) as ‘question/yes’ and どうか (dou ka) as ‘how/no’. Together, they represent the uncertainty between the two possibilities: ‘Is it X, or how is it?’ which means ‘whether or not it is X.’
Other Grammar
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