How to ask a question: In-situ interrogatives & the particle か

Mental Model: The Verbal Question Mark (No Inversion!)

In English, turning a statement into a question requires mental gymnastics: • “You are a student.” → Invert subject and verb: “Are you a student?” • “You drink coffee.” → Invent do-support: “Do you drink coffee?”

In Japanese, word order never changes:

• Take the exact statement as it stands.
• Attach the particle か to the very end of the sentence.
• か acts as an audible, spoken question mark: Statement: 田中さんは 学生です。(たなかさんは がくせいです。) (“Mr. Tanaka is a student.”) → Question: 田中さんは 学生ですか。(たなかさんは がくせいですか。) (“Is Mr. Tanaka a student?”).

In-Situ Interrogatives: Words Stay Where Answers Sit

When asking open-ended questions with “what,” “who,” or “when,” English pulls the question word all the way to the front of the sentence (“What did you buy?”).

In Japanese, the question word stands in-situ (in the exact grammatical position where the answer noun will go):

• Statement: 本を 買いました。(ほんを かいました。) (“I bought a book.”)
• Question: 何を 買いましたか。(なにを かいましたか。) (“What did you buy?”)
• Statement: 明日 行きます。(あした いきます。) (“I will go tomorrow.”)
• Question: いつ 行きますか。 (“When will you go?”).

The Six Essential Question Roots

Master the foundational interrogatives of Japanese:

• What: 何(なに / なん) (これは 何ですか。 = “What is this?”)
• Who: 誰(だれ) (あの人は 誰ですか。 = “Who is that person?”)
• Where: どこ (駅は どこですか。 = “Where is the station?”)
• When: いつ (誕生日は いつですか。(たんじょうびは いつですか。) = “When is your birthday?”)
• Why: どうして / なぜ (どうして 日本語を 勉強しますか。 = “Why do you study Japanese?”)
• How: どう (日本の生活は どうですか。(にほんのせいかつは どうですか。) = “How is life in Japan?”).

The Golden Rule: Question Words Never Take は

Because question words represent unknown, new information, they cannot be marked with the topic particle は! They must be marked with the identifier particle が:

• Wrong: *誰は 来ますか。
• Correct: 誰が 来ますか。(だれが きますか。) (“Who is coming?”)
• Wrong: *どれは あなたの 傘ですか。
• Correct: どれが あなたの 傘ですか。(どれが あなたの かさですか。) (“Which one is your umbrella?”).