説とき起おこす

godan verb (-su), intransitive verb

begin to explain; start telling (a story); launch into an argument

Used when someone starts explaining or narrating something, often with a sense of setting the stage or building up from the beginning. Common in formal or literary contexts.

• 彼かれは事じ件けんの経けい緯いを説とき起おこした。

  He began to explain the circumstances of the incident.

• 先せん生せいは古こ代だいの歴れき史しを説とき起おこした。

  The teacher launched into an explanation of ancient history.