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いつ
itsu
when
いつ日本に来ますか？
When will you come to Japan?
neutral
At what time; on what occasion
いつ会いましょうか？
When shall we meet?
いつまでに終わらせますか？
By when will you finish it?
Used for questions about time. Can be combined with particles like に, から, まで, or の.
neutral
Sometime (in the future)
いつかまた会いましょう。
Let's meet again sometime.
Often used with か to indicate uncertainty or future possibility.
Pro Tip
Combining with particles
いつ + に = specific time (いつに？). いつ + から = from when (いつから？). いつ + まで = until when (いつまで？).
Word Origin
From Old Japanese *itu*, related to Proto-Japonic *itu. Cognate with Korean 언제 (eonje) and possibly with Proto-Turkic *neče (when).
Usage Notes
いつ is a time-related interrogative adverb. It cannot be used alone in polite questions; typically followed by a verb or particle. In casual speech, it may stand alone in questions (e.g., いつ？).
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