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.
Which one would you like?
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.
Which book is yours?
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.
The speaker wants to identify a specific person from a group.
Means 'which person'. Neutral and commonly used.
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).
Which one is yours?
Which color do you like?
Which one do you want, red or blue?
Which one is correct?
Polite/formal version of どっち. Used in formal situations or when showing respect.
Which one would be better?
Which way is the restroom?
Which person is the teacher?
Polite way to say 'which person' or 'who'. Used in formal contexts.
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.
Who is the fastest among these?
I don't know which one is correct.
Please tell me which one I should choose.
Embedded question for two choices. Casual.
I can't tell which one is the real one.
Which one will you take? (from two)
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.
Which one do you want, tea or coffee?
I can't decide which one to buy.