それはそうとThat aside; anyway
それはそうと acknowledges the current topic, deliberately sets it aside, and introduces a different matter. It often corresponds to “that aside” or “anyway.”
How it works
The opening それ points back to what has just been discussed. The speaker briefly recognizes that topic, then signals that it will not be pursued for now. What follows should therefore be a genuinely different matter, often one that feels more urgent or practical.
A deliberate switch
昨日の映画、最後の場面がよかったね。
Yesterday’s movie had a great final scene.
Analyzeうん。それはそうと、今日の宿題はもう出した？
Yeah. That aside, have you turned in today’s homework yet?
AnalyzeThe homework question is not presented as something suggested by the movie. The speaker intentionally leaves the movie discussion and turns to a more immediate concern.
Remembering something versus breaking away
そういえば introduces something that the preceding topic has brought to mind. By contrast, それはそうと deliberately cuts off the old thread. The topics can be similar in both situations; the difference is whether the speaker presents the new thought as an association or as an intentional switch.
新しいオフィスの話で思い出した。そういえば、明日の会議は何時から？
Talking about the new office reminded me: what time does tomorrow’s meeting start?
AnalyzeHere the meeting question is presented as a recollection prompted by the office discussion, not as a deliberate interruption.
新しいオフィスの話はまた今度にしよう。それはそうと、明日の会議は何時から？
Let’s leave the new office discussion for another time. That aside, what time does tomorrow’s meeting start?
AnalyzeKeep the expression fixed
Do not insert the name of the old topic into this connective. When you need to name the exact item being set aside, use the separate pattern 費用はさておき. With the target expression, the previous conversation itself supplies what それ refers to.
More examples
新しい店の料理はおいしかったね。それはそうと、帰りのバスはまだあるかな。
The food at the new restaurant was good. That aside, I wonder if there’s still a bus home.
Analyze企画の細かい点は午後に確認しましょう。それはそうと、先方への連絡は済みましたか。
Let’s check the details of the plan this afternoon. In the meantime, have you contacted the other party?
Analyze彼の引っ越し先についてしばらく話した。それはそうと、締め切りは明日だったと思い出した。
We talked for a while about where he was moving. Then I put that aside and remembered that the deadline was tomorrow.
Analyze写真の整理は週末にやればいいよ。それはそうと、鍵はちゃんと持った？
You can organize the photos this weekend. More importantly for now, do you have your key?
Analyzeその問題についてはあとで話そう。それはそうと、体調はもう大丈夫なの？
Let’s discuss that problem later. Putting that aside, are you feeling all right now?
Analyze