Japatan
Formation
- N / なA + だ・だった + っけ
- いA(〜かった) + っけ
- Vた形 + っけ
- V普通形 + んだ + っけ
- 丁寧形: 〜でしたっけ・〜ましたっけ
Explanation
Used to check something you once knew but have forgotten, asking another person or yourself. It is casual spoken Japanese; with superiors use 〜でしたっけ or 〜ましたっけ. A second use, often with よく〜たっけ, is fondly remembering the past.
Examples
旅行は来週の何曜日に 出発するんだっけ？
What day next week are we leaving on the trip again?
あれ、今日は何曜日 だっけ？
Huh, what day is it today again?
すみません、佐藤さんの誕生日は何日 でしたっけ？
Excuse me, what date is Sato's birthday again?
子どものころは、よくこの川で 遊んだっけ。
When I was a child, I used to play in this river a lot.
Notes
Rather than adding っけ directly to the dictionary form, it is normal to insert んだ: 行くんだっけ. It is not used in formal writing.
Mini quiz
1あれ、この店、前は何の店（ ）っけ？
Answer and explanation
Answer: 1 だった
Huh, what kind of shop was this before? A noun takes だ or だった before っけ, so 何の店だったっけ is correct.
2すみません、次の会議は何日（ ）？
Answer and explanation
Answer: 3 でしたっけ
Excuse me, what date is the next meeting again? The polite form is でしたっけ. っけ does not attach to でしょう, だろう, or ます.
3鍵、どこに（ ）っけ。
Answer and explanation
Answer: 2 置いた
Where did I put my key again? The speaker is trying to remember a past action, so the た form 置いたっけ is correct. っけ does not attach to 置いて or 置き.
