speaking of which
01
そういえば, ちなみに
used to smoothly transition from one topic to another, often when the second topic is related to or follows naturally from the first
Collocation
例
I heard you 're planning a trip to Europe. Speaking of which, have you decided which cities you'll visit?
ヨーロッパへの旅行を計画していると聞きました。そういえば、どの都市を訪れるか決めましたか？
