Japanese · Question Words
itsu
When
The question word used to ask about time. It can refer to a specific point in time or a duration, and does not require a particle in most cases.
パーティーはいつですか?
When is the party?
'いつ' (itsu) derives from ancient forms of time inquiry and has developed to address various temporal situations.
'いつ' is common in both spoken and written contexts, mostly in informal conversations to inquire about time, and is widely understood.