どの
Which (of three or more), What (kind)
Structure
Explanation
In Japanese, どの is known as a 'pre-noun adjectival'. This means it is a word that directly precedes a noun and does not have different conjugations; its form is always fixed. It belongs to the same group of interrogative words as どれ (which one) and どこ (where), and is used to ask 'which' specific item is being selected from a group.
- どの本がおもしろい？Which book is interesting?
- どの席でも大丈夫です。Any seat is fine.
As demonstrated above, どの can be used not only to form questions but also to express the idea of 'any' or 'whichever' when making a statement.
Caution
It is important to remember that どの is reserved for situations with three or more options. When choosing between only two items, どっち（の） or どちら（の） should be used.
- コーヒーとお茶、どっちにする？Coffee or tea, which will you have?
- どの科目がいちばん得意？Which subject are you best at?
In the first sentence, the choice is explicitly limited to two options (coffee or tea), so どっち is the correct word. The second sentence, however, asks about a category with many possibilities (school subjects), making どの the appropriate choice.
Examples
どの道が近いですか。
Which road is shorter?
どのバスに乗る？
Which bus are you taking?
どの映画を見ますか。
Which movie will you watch?
どの色が好きですか。
Which color do you like?
どの傘を使いますか。
Which umbrella will you use?
どの階に住んでいるんですか。
Which floor do you live on?
どの季節が一番好きですか。
Which season do you like the most?
どのお店で買うんですか。
At which store are you going to buy it?
どの席が空いていますか。
Which seat is available?
どのカバンが軽い？
Which bag is light?
どの犬が欲しいですか。
Which dog do you want?
先生：「どの本を読みましたか？」学生：「この赤い本を読みました。」
Teacher: 'Which book did you read?' Student: 'I read this red book.'