Translation guide
In Japanese, asking 'which one' depends on the number of choices and the type of thing being referred to. The most common way is to use どれ (dore) for three or more items, or どっち (docchi) for two items. For people, use どの人 (dono hito) or どなた (donata) politely. The question can also be embedded in longer sentences.
The speaker wants to know which specific item or option is being referred to, from a set of three or more.
The standard interrogative pronoun for 'which one' when there are three or more choices. It can stand alone or be used as a noun.
どれがいいですか。
Which one would you like?
この中でどれが一番好きですか。
Which one do you like best among these?
Use どの before a noun to ask 'which [noun]' when there are three or more. It specifies the category of the item.
どの本があなたのですか。
Which book is yours?
どの色が好きですか。
Which color do you like?
The speaker wants to know which of two specific options is chosen.
Casual/interrogative for 'which one' when there are exactly two choices. Often used in everyday speech.
赤と青、どっちがいい？
Which one do you want, red or blue?
どっちが正しいですか。
Which one is correct?
Polite/formal version of どっち. Used in formal situations or when showing respect.
どちらがよろしいですか。
Which one would be better?
The speaker wants to identify a specific person from a group.
Means 'which person'. Neutral and commonly used.
どの人が先生ですか。
Which person is the teacher?
Polite way to say 'which person' or 'who'. Used in formal contexts.
どなたが担当者ですか。
Which person is in charge?
Means 'who', but can be used in contexts like 'which one (person)' when the set of people is understood. Casual.
The speaker is reporting or asking about a choice indirectly, e.g., 'I don't know which one' or 'Tell me which one'.
Means 'which one' in an embedded question. Often used with verbs like わかる (understand) or 決める (decide).
どれが正しいかわかりません。
I don't know which one is correct.
どれを選べばいいか教えてください。
Please tell me which one I should choose.
Embedded question for two choices. Casual.
どっちが本物か見分けがつかない。
I can't tell which one is the real one.
どれ is used alone for three or more items. どっち is for two items. どの must be followed by a noun and works for three or more. For two items, you can also use どちらの + noun (polite).
どれにしますか。
Which one will you take? (from many)
どっちにしますか。
Which one will you take? (from two)
どの車が好きですか。
Which car do you like? (from many)
Using どれ when there are only two choices sounds unnatural. Use どっち or どちら instead.
どれがあなたのですか。
Which one is yours?
紅茶とコーヒー、どっちがいい？
Which one do you want, tea or coffee?
どれを買うか決められない。
I can't decide which one to buy.
お手洗いはどちらですか。
Which way is the restroom?
Who is the fastest among these?