Jolloin

Jolloin is a Finnish adverbial conjunction that means "at that time," "then," or "in that case." It is used to refer to a specific moment within a sentence and often appears in relative clauses or to mark a consequential moment in narration.

The word is more common in written Finnish and is considered slightly formal compared with the everyday kun ("when"). It introduces a temporal clause referring back to a previously mentioned time or event, for example in relative constructions such as "päivän, jolloin kaikki muuttui" (the day on which everything changed).

Examples: "Hän muisti päivän, jolloin kaikki alkoi." (He remembered the day when everything began.) "Sää oli silloin hyvä, jolloin matka sujui nopeasti." (The weather was good then, so the journey went quickly.)

Usage notes: Because of its nuance, jolloin often conveys a defined, remembered, or hypothetical moment rather than a general time reference, and it may be preferred in narrative or formal writing. It is related to kun, with the key difference that kun signals general time while jolloin emphasizes a particular moment or event within that time frame.